["CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 45: Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a CLLX th\u00ec: A. C\u01a1 n\u0103ng v\u00e0 \u0111\u1ed9ng n\u0103ng bi\u1ebfn thi\u00ean tu\u1ea7n ho\u00e0n c\u00f9ng t\u1ea7n s\u1ed1, t\u1ea7n s\u1ed1 \u0111\u00f3 g\u1ea5p \u0111\u00f4i t\u1ea7n s\u1ed1 dao \u0111\u1ed9ng B. Sau m\u1ed7i l\u1ea7n v\u1eadt \u0111\u1ed5i chi\u1ec1u, c\u00f3 2 th\u1eddi \u0111i\u1ec3m t\u1ea1i \u0111\u00f3 c\u01a1 n\u0103ng g\u1ea5p hai l\u1ea7n \u0111\u1ed9ng n\u0103ng C. Khi \u0111\u1ed9ng n\u0103ng t\u0103ng, c\u01a1 n\u0103ng gi\u1ea3m v\u00e0 ng\u01b0\u1ee3c l\u1ea1i D. C\u01a1 n\u0103ng c\u1ee7a v\u1eadt b\u1eb1ng \u0111\u1ed9ng n\u0103ng khi v\u1eadt \u0111\u1ed5i chi\u1ec1u chuy\u1ec3n \u0111\u1ed9ng C\u00e2u 46: Trong chuy\u1ec3n \u0111\u1ed9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a m\u1ed9t v\u1eadt th\u00ec t\u1eadp h\u1ee3p ba \u0111\u1ea1i l\u01b0\u1ee3ng sau \u0111\u00e2y l\u00e0 kh\u00f4ng thay \u0111\u1ed5i theo th\u1eddi gian: A. V\u1eadn t\u1ed1c, l\u1ef1c, n\u0103ng l\u01b0\u1ee3ng to\u00e0n ph\u1ea7n B. Gia t\u1ed1c, chu k\u00ec, l\u1ef1c C. Bi\u00ean \u0111\u1ed9, t\u1ea7n s\u1ed1, n\u0103ng l\u01b0\u1ee3ng to\u00e0n ph\u1ea7n D. Bi\u00ean \u0111\u1ed9, t\u1ea7n s\u1ed1, gia t\u1ed1c C\u00e2u 47: Trong dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a nh\u1eefng \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0o dao \u0111\u1ed9ng c\u00f9ng t\u1ea7n s\u1ed1 v\u1edbi li \u0111\u1ed9: A. V\u1eadn t\u1ed1c, gia t\u1ed1c v\u00e0 c\u01a1 n\u0103ng. B. V\u1eadn t\u1ed1c, \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng. C. V\u1eadn t\u1ed1c, gia t\u1ed1c v\u00e0 l\u1ef1c k\u00e9o v\u1ec1. D. \u0110\u1ed9ng n\u0103ng, th\u1ebf n\u0103ng v\u00e0 l\u1ef1c k\u00e9o v\u1ec1 C\u00e2u 48: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf v\u00e0 l\u00f2 xo nh\u1eb9, \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. \u0110\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc \u0111\u1ea1t gi\u00e1 tr\u1ecb c\u1ef1c ti\u1ec3u khi: A. L\u00f2 xo kh\u00f4ng bi\u1ebfn d\u1ea1ng. B. V\u1eadt c\u00f3 v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i. C. V\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. D. L\u00f2 xo c\u00f3 chi\u1ec1u d\u00e0i c\u1ef1c \u0111\u1ea1i. C\u00e2u 49: M\u1ed9t ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean tr\u1ee5c Ox v\u1edbi bi\u00ean \u0111\u1ed9 A, chu k\u00ec T. Khi v\u1eadt chuy\u1ec3n \u0111\u1ed9ng ch\u1eadm d\u1ea7n theo chi\u1ec1u \u00e2m \u0111\u1ebfn v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng g\u1ea5p 3 l\u1ea7n th\u1ebf n\u0103ng th\u00ec li \u0111\u1ed9 c\u1ee7a ch\u1ea5t \u0111i\u1ec3m l\u00e0: A. A B. \u2212 A C. A 3 D. \u2212 A 3 2 2 2 2 C\u00e2u 50: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, bi\u1ebft l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=36N\/m v\u00e0 v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g. L\u1ea5y \u03c02=10. \u0110\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc bi\u1ebfn thi\u00ean theo th\u1eddi gian v\u1edbi t\u1ea7n s\u1ed1 A. 6 Hz B. 3Hz C. 12Hz D. 1Hz C\u00e2u 51: M\u1ed9t CLLX dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 10cm, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=1kg. Th\u1eddi gian ng\u1eafn nh\u1ea5t v\u1eadt \u0111i t\u1eeb t\u1ecda \u0111\u1ed9 -10cm \u0111\u1ebfn t\u1ecda \u0111\u1ed9 +10cm l\u00e0 \u03c0\/10 (s). T\u00ednh c\u01a1 n\u0103ng dao \u0111\u1ed9ng: A. 0.5J B. 0,16J C. 0,3J D. 0,36J C\u00e2u 52: Con l\u1eafc l\u00f2 xo g\u1ed3m m\u1ed9t v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 250 g v\u00e0 l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 100 N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox v\u1edbi bi\u00ean \u0111\u1ed9 4 cm. Kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 gi\u00e1 tr\u1ecb t\u1eeb \u221240 cm\/s \u0111\u1ebfn 40 3 cm\/s l\u00e0 \uf070 \uf070 \uf070 \uf070 A. s. B. s. C. s. D. s. 40 120 20 60 C\u00e2u 53: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m vi\u00ean bi v\u00e0 l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 10cm. M\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi vi\u00ean bi c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 7cm th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc b\u1eb1ng: A. 0,255J B. 3,2mJ C. 25,5mJ D. 0,32J C\u00e2u 54: M\u1ed9t v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng 100 g, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng tr\u00ecnh x = 8cos(10t ) ( x t\u00ednh b\u1eb1ng cm, t t\u00ednh b\u1eb1ng s). \u0110\u1ed9ng n\u0103ng c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt b\u1eb1ng A. 32 mJ. B. 16 mJ. C. 64 mJ. D. 128 mJ. C\u00e2u 55: M\u1ed9t con l\u1eafc l\u00f2 xo c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt nh\u1ecf l\u00e0 50 g. Con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo m\u1ed9t tr\u1ee5c c\u1ed1 \u0111\u1ecbnh n\u1eb1m ngang v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x = A cos(\uf077t ) . C\u1ee9 sau nh\u1eefng kho\u1ea3ng th\u1eddi gian 0,05 s th\u00ec \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng c\u1ee7a v\u1eadt l\u1ea1i b\u1eb1ng nhau. L\u1ea5y \uf0702 = 10 . L\u00f2 xo c\u1ee7a con l\u1eafc c\u00f3 \u0111\u1ed9 c\u1ee9ng b\u1eb1ng A. 50 N\/m. B. 100 N\/m. C. 25 N\/m. D. 200 N\/m. TRANG 49","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 56: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng m = 100 gam v\u00e0 l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 100 N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 9cm. L\u1ea5y g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac con l\u1eafc \u0111ang \u0111i theo chi\u1ec1u d\u01b0\u01a1ng c\u1ee7a tr\u1ee5c t\u1ecda \u0111\u1ed9, t\u1ea1i \u0111\u00f3 th\u1ebf n\u0103ng b\u1eb1ng ba l\u1ea7n \u0111\u1ed9ng n\u0103ng v\u00e0 c\u00f3 t\u1ed1c \u0111\u1ed9 \u0111ang gi\u1ea3m. L\u1ea5y \u03c02 = 10. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. x = 9cos(10\u03c0t \u2212 \u03c0\/6) cm. B. x = 9cos(10\u03c0t + \u03c0\/6) cm. C. x = 9cos(10\u03c0t \u2013 5\u03c0\/6) cm. D. x = 9cos(10\u03c0t + 5\u03c0\/6) cm. C\u00e2u 57: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 100 N\/m v\u00e0 v\u1eadt nh\u1ecf dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a Khi v\u1eadt c\u00f3 \u0111\u1ed9ng n\u0103ng 0,01 J th\u00ec n\u00f3 c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 1 cm. H\u1ecfi khi n\u00f3 c\u00f3 \u0111\u1ed9ng n\u0103ng 0,005 J th\u00ec n\u00f3 c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng bao nhi\u00eau? A. 6cm. B. 4,5cm C. 2 cm D. 3cm. C\u00e2u 58: V\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee9 m\u1ed7i ph\u00fat th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 120 dao \u0111\u1ed9ng. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn c\u1ef1c \u0111\u1ea1i l\u00e0 20\u03c0 (cm\/s). Khi \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt g\u1ea5p 3 l\u1ea7n th\u1ebf n\u0103ng th\u00ec n\u00f3 \u1edf c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n A. 2,9 cm. B. 4,33 cm. C. 2,5 cm. D. 3,53 cm. C\u00e2u 59: M\u1ed9t v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng m = 200 g \u0111\u01b0\u1ee3c treo v\u00e0o m\u1ed9t l\u00f2 xo kh\u1ed1i l\u01b0\u1ee3ng kh\u00f4ng \u0111\u00e1ng k\u1ec3, \u0111\u1ed9 c\u1ee9ng k. K\u00edch th\u00edch \u0111\u1ec3 con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi gia t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 16 m\/s2 v\u00e0 c\u01a1 n\u0103ng b\u1eb1ng 64 mJ. \u0110\u1ed9 c\u1ee9ng l\u00f2 xo v\u00e0 v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt l\u1ea7n l\u01b0\u1ee3t l\u00e0 A. 40 N\/m; 1,6 m\/s. B. 40 N\/m; 16 m\/s. C. 80 N\/m; 8 m\/s. D. 80 N\/m; 80 cm\/s. C\u00e2u 60: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc tr\u1ee5c Ox, m\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. \u1ede th\u1eddi \u0111i\u1ec3m \u0111\u1ed9 l\u1edbn v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt b\u1eb1ng 50% v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i th\u00ec t\u1ef7 s\u1ed1 gi\u1eefa \u0111\u1ed9ng n\u0103ng v\u00e0 c\u01a1 n\u0103ng c\u1ee7a v\u1eadt l\u00e0: A. 3\/4 B. 1\/4 C. 4\/3 D. 1\/2 C\u00e2u 61: V\u1eadt nh\u1ecf c\u1ee7a m\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang, m\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi gia t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn b\u1eb1ng m\u1ed9t n\u1eeda \u0111\u1ed9 l\u1edbn gia t\u1ed1c c\u1ef1c \u0111\u1ea1i th\u00ec t\u1ec9 s\u1ed1 gi\u1eefa \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng c\u1ee7a v\u1eadt l\u00e0: A. 1\/2 B. 3 C. 2 D. 1\/3 C\u00e2u 62: M\u1ed9t con l\u1eafc l\u00f2 xo, \u0111\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo 9 N\/m, kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt 1kg dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. T\u1ea1i th\u1eddi \u0111i\u1ec3m v\u1eadt c\u00f3 t\u1ecda \u0111\u1ed9 2 3 cm th\u00ec v\u1eadt c\u00f3 v\u1eadn t\u1ed1c 6cm\/s. T\u00ednh c\u01a1 n\u0103ng c\u1ee7a v\u1eadt A. 10mJ B. 20mJ C. 7,2mJ D. 72mJ C\u00e2u 63: M\u1ed9t v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1kg dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang. L\u00fac \u0111\u1ea7u t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng ng\u01b0\u1eddi ta k\u00e9o v\u1eadt theo ph\u01b0\u01a1ng ngang 4cm r\u1ed3i bu\u00f4ng nh\u1eb9. Sau th\u1eddi gian t= \u03c0\/30 (s) k\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m bu\u00f4ng v\u1eadt \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng 6cm. C\u01a1 n\u0103ng c\u1ee7a v\u1eadt l\u00e0: A. 0,16J B. 0,32J C. 0,48J D. 0,54J C\u00e2u 64: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 A d\u1ecdc theo tr\u1ee5c 0x. Th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111i t\u1eeb v\u1ecb tr\u00ed x= 0 \u0111\u1ebfn v\u1ecb tr\u00ed x= 0,5A 3 l\u00e0 \u03c0\/6 (s). T\u1ea1i \u0111i\u1ec3m c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 2cm th\u00ec v\u1eadt c\u00f3 v\u1eadn t\u1ed1c l\u00e0 4 3 cm\/s. Kh\u1ed1i l\u01b0\u1ee3ng qu\u1ea3 c\u1ea7u l\u00e0 100g. N\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng c\u1ee7a n\u00f3 l\u00e0: A. 0,32 mJ B. 0,16 mJ C. 0,26 mJ D. 0,36 mJ C\u00e2u 65: M\u1ed9t CLLX n\u1eb1m ngang g\u1ed3m v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1kg v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng K=100\u03c02 N\/m. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o v\u1eadt theo ph\u01b0\u01a1ng ngang m\u1ed9t \u0111o\u1ea1n b\u1eb1ng A, r\u1ed3i th\u1ea3 nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Sau kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t b\u1eb1ng bao nhi\u00eau, k\u1ec3 t\u1eeb l\u00fac th\u1ea3 v\u1eadt th\u00ec \u0111\u1ed9ng n\u0103ng v\u1eadt b\u1eb1ng 3 l\u1ea7n th\u1ebf n\u0103ng: A. 1\/15 s B. 1\/30 s C. 1\/60 s D. 2\/15 s TRANG 50","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 66: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 20N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 3Hz. Trong m\u1ed9t chu k\u00ec, kho\u1ea3ng th\u1eddi gian \u0111\u1ec3 v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn gia t\u1ed1c kh\u00f4ng v\u01b0\u1ee3t qu\u00e1 360 3 cm\/s2 l\u00e0 2\/9s. L\u1ea5y \u03c02=10. N\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng l\u00e0: A. 4mJ B. 2mJ C. 6mJ D. 8mJ C\u00e2u 67: M\u1ed9t con l\u1eafc l\u00f2 xo nh\u1eb9 v\u00e0 v\u1eadt nh\u1ecf dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang v\u1edbi t\u1ea7n s\u1ed1 g\u00f3c 10 rad\/s. Bi\u1ebft r\u1eb1ng khi \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng b\u1eb1ng nhau th\u00ec v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn b\u1eb1ng 0,6 m\/s. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 6 2 cm B. 6 cm C. 12cm D. 3 2 cm C\u00e2u 68: M\u1ed9t con l\u1eafc l\u00f2 xo b\u1ed1 tr\u00ed n\u1eb1m ngang, v\u1eadt m=100g. V\u1eadt dao \u0111\u1ed9ng v\u1edbi v=5\u03c0cos( \u03c0t + \u03c0\/6) cm\/s. T\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a v\u1eadt t\u00ednh t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u \u0111\u1ebfn v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng 1\/3 th\u1ebf n\u0103ng l\u1ea7n th\u1ee9 2 l\u00e0: A. 6,34 cm\/s B. 21,12 cm\/s C. 15,74 cm\/s D. 3,66 cm\/s C\u00e2u 69: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox n\u1eb1m ngang. C\u1ee9 sau kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t l\u00e0 0,5s th\u00ec \u0111\u1ed9ng n\u0103ng l\u1ea1i b\u1eb1ng th\u1ebf n\u0103ng v\u00e0 c\u0169ng trong kho\u1ea3ng th\u1eddi gian 0,5s v\u1eadt \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng d\u00e0i nh\u1ea5t l\u00e0 4 2 cm. Ch\u1ecdn t=0 l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng theo chi\u1ec1u d\u01b0\u01a1ng. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. x=4cos(\u03c0t \u2013 \u03c0\/2) (cm). B. x=2cos(\u03c0t \u2013 \u03c0\/2) (cm). C. x=4cos(2\u03c0t \u2013 \u03c0\/2) (cm) D. x=2cos(2\u03c0t + \u03c0\/2) (cm) C\u00e2u 70: M\u1ed9t ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean tr\u1ee5c 0x v\u1edbi bi\u00ean \u0111\u1ed9 10cm, chu k\u00ec T=2s. M\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. T\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a ch\u1ea5t \u0111i\u1ec3m trong kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t khi ch\u1ea5t \u0111i\u1ec3m \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng 3 l\u1ea7n th\u1ebf n\u0103ng \u0111\u1ebfn v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng 1\/3 l\u1ea7n th\u1ebf n\u0103ng: A. 26,12 cm\/s B. 7,32 cm\/s C. 14,64 cm\/s D. 21,96 cm\/s C\u00e2u 71: M\u1ed9t ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i 60cm\/s v\u00e0 gia t\u1ed1c c\u1ef1c \u0111\u1ea1i l\u00e0 2\u03c0 (m\/s2). Ch\u1ecdn m\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Th\u1eddi \u0111i\u1ec3m \u0111\u1ea7u ti\u00ean v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 v\u1eadn t\u1ed1c 30cm\/s v\u00e0 th\u1ebf n\u0103ng \u0111ang t\u0103ng. Ch\u1ea5t \u0111i\u1ec3m c\u00f3 gi\u00e1 t\u1ed1c b\u1eb1ng \u03c0 (m\/s2) l\u1ea7n \u0111\u1ea7u ti\u00ean \u1edf th\u1eddi \u0111i\u1ec3m: A. 0,35s B. 0,15s C. 0,10s D. 0,25s C\u00e2u 72: V\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 3 m\/s v\u00e0 gia t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 30\u03c0 (m\/s2). L\u00fac t = 0 v\u1eadt c\u00f3 v\u1eadn t\u1ed1c v1 = +1,5 m\/s v\u00e0 th\u1ebf n\u0103ng \u0111ang gi\u1ea3m. H\u1ecfi sau th\u1eddi gian ng\u1eafn nh\u1ea5t l\u00e0 bao nhi\u00eau th\u00ec v\u1eadt c\u00f3 gia t\u1ed1c b\u1eb1ng \u2212 15\u03c0 (m\/s2)? A. 0,05 s. B. 0,15 s. C. 0,10 s. D. 1\/12 s. C\u00e2u 73: M\u1ed9t con l\u1eafc l\u00f2 xo b\u1ed1 tr\u00ed n\u1eb1m ngang, c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 50g dao \u0111\u00f4ng \u0111i\u1ec1u h\u00f2a. Th\u1ea5y r\u1eb1ng c\u1ee9 sau nh\u1eefng kho\u1ea3ng th\u1eddi gian 0,05s th\u00ec \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng l\u1ea1i b\u1eb1ng nhau. L\u1ea5y \u03c02=10. \u0110\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo l\u00e0: A. 25 N\/m B. 200 N\/m C. 100N\/m D. 50 N\/m C\u00e2u 74: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x = 10 cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 cm, t \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng gi\u00e2y. K\u1ec3 \uf0e7\uf0e8 2 \uf0f7\uf0f8 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, qu\u00e3ng \u0111\u01b0\u1eddng m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c cho t\u1edbi khi v\u1eadt \u0111i qua v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng ba l\u1ea7n th\u1ebf n\u0103ng l\u1ea7n \u0111\u1ea7u ti\u00ean l\u00e0 A. 10 cm. B. 5 cm. C. 20 cm. D. 25 cm. C\u00e2u 75: M\u1ed9t v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng 100 g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec 0,2 s v\u00e0 c\u01a1 n\u0103ng l\u00e0 0,18 J (m\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng); l\u1ea5y \uf0702 = 10 . T\u1ea1i li \u0111\u1ed9 3 2 cm, t\u1ec9 s\u1ed1 \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng l\u00e0 A. 1. B. 4. C. 3. D. 2. TRANG 51","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 76: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 6cm. M\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi v\u1eadt c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng 3\/4 l\u1ea7n c\u01a1 n\u0103ng th\u00ec v\u1eadt c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n: A. 6cm B. 4,5cm C. 4cm D. 3cm C\u00e2u 77: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 A d\u1ecdc theo tr\u1ee5c Ox (O l\u00e0 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng). Th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111i t\u1eeb v\u1ecb tr\u00ed x = 0 \u0111\u1ebfn v\u1ecb tr\u00ed x = 0,5A 3 l\u00e0 \u03c0\/6 (s). T\u1ea1i \u0111i\u1ec3m c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 2 cm th\u00ec n\u00f3 c\u00f3 v\u1eadn t\u1ed1c l\u00e0 4 3 cm\/s. Kh\u1ed1i l\u01b0\u1ee3ng qu\u1ea3 c\u1ea7u l\u00e0 100 g. N\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng c\u1ee7a n\u00f3 l\u00e0 A. 0,32 mJ. B. 0,16 mJ. C. 0,26 mJ. D. 0,36 mJ. C\u00e2u 78: V\u1eadt nh\u1ecf v\u1edbi kh\u1ed1i l\u01b0\u1ee3ng 1kg th\u1ef1c hi\u1ec7n dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng tr\u00ecnh x=Acos4t (cm). Bi\u1ebft qu\u00e3ng \u0111\u01b0\u1eddng l\u1edbn nh\u1ea5t m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c trong m\u1ed9t ph\u1ea7n t\u01b0 chu k\u00ec l\u00e0 0,1 2 m. C\u01a1 n\u0103ng c\u1ee7a v\u1eadt b\u1eb1ng: A. 0,16J B. 0,72J C. 0,045J D. 0,08J C\u00e2u 79: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt n\u1eb7ng 0,2kg g\u1eafn v\u00e0o \u0111\u1ea7u l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 20N\/m. K\u00e9o qu\u1ea3 n\u1eb7ng ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng r\u1ed3i th\u1ea3 nh\u1eb9 cho n\u00f3 dao \u0111\u1ed9ng, t\u1ed1c \u0111\u1ed9 trung b\u00ecnh trong 1 chu k\u00ec l\u00e0 160\/\u03c0 (cm\/s). C\u01a1 n\u0103ng dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 320J B. 6,4.10-2J C. 3,2.10-2J D. 3,2J C\u00e2u 80: V\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a th\u1ef1c hi\u1ec7n 10 dao \u0111\u1ed9ng trong 5s, khi v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec n\u00f3 c\u00f3 t\u1ed1c \u0111\u1ed9 20\u03c0 cm\/s. Ch\u1ecdn g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 x = 2,5 3 cm v\u00e0 \u0111ang chuy\u1ec3n \u0111\u1ed9ng v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. V\u1eadt c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng ba l\u1ea7n th\u1ebf n\u0103ng l\u1ea7n th\u1ee9 hai k\u1ec3 t\u1eeb khi b\u1eaft \u0111\u1ea7u dao \u0111\u1ed9ng t\u1ea1i th\u1eddi \u0111i\u1ec3m: A. 0,25s B. 1,25s C. 0,125s D. 2,5s C\u00e2u 81: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m = 800 g, l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 200 N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang v\u1edbi bi\u00ean \u0111\u1ed9 2 cm. Ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, tr\u1ee5c Ox d\u1ecdc theo tr\u1ee5c c\u1ee7a l\u00f2 xo v\u00e0 h\u01b0\u1edbng v\u1ec1 ph\u00eda l\u00f2 xo gi\u00e3n. Quan s\u00e1t dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc th\u00ec th\u1ea5y t\u1ea1i th\u1eddi \u0111i\u1ec3m t = 11 s v\u1eadt chuy\u1ec3n \u0111\u1ed9ng ch\u1eadm d\u1ea7n qua v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng th\u1ebf n\u0103ng theo chi\u1ec1u \u00e2m. L\u1ea5y 60 \uf0702 = 10 . Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. x = 2 cos \uf0e6\uf0e7\uf0e810\uf070t \u2212 \uf070 \uf0f6 cm. B. x = 2 cos \uf0e6 \uf070t + \uf070\uf0f6 cm. 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 C. x = 2 cos \uf0e6 5\uf070t \u2212 \uf070 \uf0f6 cm. D. x = 2 cos \uf0e6 5\uf070t \u2212 \uf070 \uf0f6 cm. \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 2 \uf0f7\uf0f8 C\u00e2u 82: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng ngang v\u1edbi c\u01a1 n\u0103ng b\u1eb1ng 20mJ, bi\u1ebft l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=100 N\/m, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=400gg. Ch\u1ecdn Ox d\u1ecdc theo tr\u1ee5c c\u1ee7a l\u00f2 xo, g\u1ed1c t\u1ecda \u0111\u1ed9 O t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt chuy\u1ec3n \u0111\u1ed9ng nhanh d\u1ea7n qua v\u1ecb tr\u00ed c\u00f3 th\u1ebf n\u0103ng b\u1eb1ng 5 mJ theo chi\u1ec1u d\u01b0\u01a1ng. L\u1ea5y \uf0702 = 10 . Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. x = 2 cos \uf0e6\uf0e7\uf0e8 5\uf070t \u2212 2\uf070 \uf0f6 cm. B. x = 2 cos \uf0e6 5\uf070t + 2\uf070 \uf0f6 cm. 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 C. x = 4 cos \uf0e6\uf0e7\uf0e8 5\uf070t + 2\uf070 \uf0f6 cm. D. x = 4 cos \uf0e6 5\uf070t \u2212 2\uf070 \uf0f6 cm. 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 C\u00e2u 83: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 4cm, c\u1ee9 sau m\u1ed9t kho\u1ea3ng th\u1eddi gian 1\/4s th\u00ec \u0111\u1ed9ng n\u0103ng l\u1ea1i b\u1eb1ng th\u1ebf n\u0103ng. Qu\u00e3ng \u0111\u01b0\u1eddng l\u1edbn nh\u1ea5t m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c trong kho\u1ea3ng th\u1eddi gian 1\/6s l\u00e0: A. 8cm B. 6cm C. 2cm D. 4cm TRANG 52","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 84: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng tr\u00ecnh x=5cos(4\u03c0t + \u03c0\/2) cm. K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, trong kho\u1ea3ng th\u1eddi gian 1,125s, s\u1ed1 l\u1ea7n v\u1eadt \u0111i qua v\u1ecb tr\u00ed m\u00e0 \u0111\u1ed9ng n\u0103ng b\u1eb1ng th\u1ebf n\u0103ng l\u00e0: A. 5 B. 4 C. 9 D. 8 C\u00e2u 85: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng tr\u00ecnh x=8cos (2\u03c0t + \u03c0\/6) (cm). T\u00ednh th\u1eddi gian \u0111\u1ec3 v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng 3 l\u1ea7n th\u1ebf n\u0103ng l\u1ea7n th\u1ee9 2022: A. 6055 s B. 6049 s C. 2021s D. 6061s 12 12 4 12 C\u00e2u 86: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng tr\u00ecnh x=10 cos (4\u03c0t \u2013\u03c0\/3) ( cm). T\u00ednh gian \u0111\u1ec3 v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng th\u1ebf n\u0103ng l\u1ea7n th\u1ee9 2022: A. 12109 B. 12103 C. 12115 D. 12127 s s s s 48 48 48 48 C\u00e2u 87: V\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 3 m\/s v\u00e0 gia t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 30\u03c0 (m\/s2). Th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt c\u00f3 v\u1eadn t\u1ed1c 1,5 m\/s v\u00e0 th\u1ebf n\u0103ng \u0111ang t\u0103ng. V\u1eadt c\u00f3 gia t\u1ed1c b\u1eb1ng 15\u03c0 (m\/s2) v\u00e0o th\u1eddi \u0111i\u1ec3m l\u1ea7n th\u1ee9 2022 l\u00e0: A. 4043 s B. 12103 s C. 12125 s D. 12121s 20 48 6 48 C\u00e2u 88: V\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 v\u1eadn. t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 3 m\/s v\u00e0 gia t\u1ed1c c\u1ef1c \u0111\u1ea1i b\u1eb1ng 30\u03c0 (m\/s2). Th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt c\u00f3 v\u1eadn t\u1ed1c \u22121,5 m\/s v\u00e0 th\u1ebf n\u0103ng \u0111ang t\u0103ng. V\u1eadt c\u00f3 gia t\u1ed1c b\u1eb1ng 15\u03c0 (m\/s2) v\u00e0o th\u1eddi \u0111i\u1ec3m l\u1ea7n th\u1ee9 2022 l\u00e0? A. 201,317 s. B. 202,183 s. C. 201,350 s. D. 201,98 s. C\u00e2u 89: Hai con l\u1eafc l\u00f2 xo gi\u1ed1ng h\u1ec7t nhau \u0111\u1eb7t tr\u00ean c\u00f9ng m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. Con l\u1eafc th\u1ee9 nh\u1ea5t v\u00e0 con l\u1eafc th\u1ee9 hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng pha v\u1edbi bi\u00ean \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 4A v\u00e0 A . Ch\u1ecdn m\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. T\u1ea1i th\u1eddi \u0111i\u1ec3m t khi th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t l\u00e0 16 mJ th\u00ec th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc th\u1ee9 hai l\u00e0 A. 2 mJ. B. 0,1 mJ. C. 1 mJ. D. 0,32 mJ. C\u00e2u 90: (VDC) M\u1ed9t ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a kh\u00f4ng ma s\u00e1t. Khi v\u1eeba qua kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n S \u0111\u1ed9ng n\u0103ng c\u1ee7a ch\u1ea5t \u0111i\u1ec3m l\u00e0 0,091J. \u0110i ti\u1ebfp m\u1ed9t \u0111o\u1ea1n 2S n\u1eefa th\u00ec \u0111\u1ed9ng n\u0103ng ch\u1ec9 c\u00f2n 0,019J. Bi\u1ebft v\u1eadt ch\u01b0a \u0111\u1ed5i chi\u1ec1u chuy\u1ec3n \u0111\u1ed9ng trong qu\u00e1 tr\u00ecnh tr\u00ean. \u0110\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt khi v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u00e0: A. 0,2J B. 0,01J C. 0,02J D. 0,1J C\u00e2u 91: (VDC) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo nh\u1eb9 v\u00e0 v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng 100 g \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang, m\u1ed1c t\u00ednh th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. T\u1eeb th\u1eddi \u0111i\u1ec3m t1 = 0 \u0111\u1ebfn t2 = \uf070 s, \u0111\u1ed9ng 48 n\u0103ng c\u1ee7a con l\u1eafc t\u0103ng t\u1eeb 0,096 J \u0111\u1ebfn gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i r\u1ed3i gi\u1ea3m v\u1ec1 0,064 J. \u1ede th\u1eddi \u0111i\u1ec3m t2, th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc b\u1eb1ng 0,064 J. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 A. 5,7 cm. B. 7,0 cm. C. 8,0 cm. D. 3,6 cm. C\u00e2u 92: (\u0110H-2018) M\u1ed9t v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 200g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 0,5Hz. Khi l\u1ef1c k\u00e9o v\u1ec1 t\u00e1c d\u1ee5ng l\u00ean v\u1eadt l\u00e0 0,1N th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt c\u00f3 gi\u00e1 tr\u1ecb 1mJ. L\u1ea5y \u03c02=10. T\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt khi \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u00e0: A. 18,7 cm\/s B. 37,4 cm\/s C. 1,89 cm\/s D. 9,35 cm\/s C\u00e2u 93: (\u0110H-2018) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 20N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec 2s. Khi pha c\u1ee7a dao \u0111\u1ed9ng l\u00e0 \u03c0\/2 th\u00ec v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt l\u00e0 -20 3 cm\/s2. L\u1ea5y \u03c02=10. Khi v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 3\u03c0 (cm) th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc l\u00e0: A. 0,36J B. 0,72J C. 0,03J D. 0,18J TRANG 53","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 94: (\u0110H-2018) M\u1ed9t v\u1eadt nh\u1ecf dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox. Khi v\u1eadt c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n 2cm th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt l\u00e0 0,48J. Khi v\u1eadt c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n 6cm th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt l\u00e0 0,32J. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 8cm B. 14cm C. 10cm D. 12cm C\u00e2u 95: M\u1ed9t con l\u1eafc l\u00f2 xo theo th\u1eb3ng \u0111\u1ee9ng (coi gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng l\u00e0 10 m\/s2) qu\u1ea3 c\u1ea7u c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 120 g. Chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a l\u00f2 xo l\u00e0 20 cm v\u00e0 \u0111\u1ed9 c\u1ee9ng 40 N\/m. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, k\u00e9o v\u1eadt th\u1eb3ng \u0111\u1ee9ng, xu\u1ed1ng d\u01b0\u1edbi t\u1edbi khi l\u00f2 xo d\u00e0i 26,5 cm r\u1ed3i bu\u00f4ng nh\u1eb9 cho n\u00f3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a \u0110\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt l\u00fac l\u00f2 xo d\u00e0i 25 cm l\u00e0: A. 24,5 mJ. B. 22 mJ. C. 12 mJ. D. 16,5 mJ. C\u00e2u 96: Quan s\u00e1t m\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 20 N\/m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a th\u00ec th\u1ea5y: t\u1ea1i th\u1eddi \u0111i\u1ec3m t1 con l\u1eafc \u0111ang chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u d\u01b0\u01a1ng v\u00e0 th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc l\u00e0 0,8 J; \u0111\u1ebfn th\u1eddi \u0111i\u1ec3m t2 = t1 + 0, 2 s th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc l\u00e0 c\u1ef1c \u0111\u1ea1i v\u00e0 b\u1eb1ng 1,6 J. Bi\u1ebft r\u1eb1ng trong kho\u1ea3ng th\u1eddi gian t\u1eeb t1 \u0111\u1ebfn t2 th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc lu\u00f4n t\u0103ng. T\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a v\u1eadt trong m\u1ed9t chu k\u00ec A. 1 m\/s. B. 2 m\/s. C. 3 m\/s. D. 4 m\/s. D\u1ea0NG 4: TH\u1edcI GIAN L\u00d2 XO D\u00c3N, N\u00c9N TRONG QU\u00c1 TR\u00ccNH DAO \u0110\u1ed8NG H\u00ccNH MINH H\u1eccA PH\u01af\u01a0NG PH\u00c1P \u2756 B\u01b0\u1edbc 1: T\u00ednh \uf044 o = m.g = g ( m\u00e9t ) K w2 \u2756 B\u01b0\u1edbc 2: T\u00ednh g\u00f3c \u03b1 \uf061 Shift cos o A \u2756 B\u01b0\u1edbc 3: Trong M\u1ed8T CHU K\u00cc th\u1eddi gian: + L\u00f2 xo n\u00e9n: t ne\u00f9n 2\uf061.T 360 + L\u00f2 xo d\u00e3n: t da\u00f5n (360 2\uf061).T 360 + T\u1ef7 l\u1ec7: tne\u00f9n 2\uf061 tda\u00f5n 360 2\uf061 C\u00e2u 97: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng sau 0,3 s th\u00ec \u0111\u1ed9ng n\u0103ng l\u1ea1i b\u1eb1ng th\u1ebf n\u0103ng (g\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng). V\u1eadt dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 6 cm, t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng \u0111\u1ed9 gi\u00e3n c\u1ee7a l\u00f2 xo l\u00e0 3 cm. Th\u1eddi gian l\u00f2 xo gi\u00e3n trong m\u1ed9t chu k\u00ec l\u00e0 A. 0,8 s. B. 1 s. C. 1,2 s. D. 1,4 s. C\u00e2u 98: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m, v\u1eadt dao \u0111\u1ed9ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g, l\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=\u03c02=10m\/s2. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o xu\u1ed1ng m\u1ed9t \u0111o\u1ea1n 1cm r\u1ed3i truy\u1ec1n cho v\u1eadt v\u1eadn t\u1ed1c ban \u0111\u1ea7u 10\u03c0 3 cm\/s h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng th\u00ec v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Th\u1eddi gian l\u00f2 xo b\u1ecb n\u00e9n trong m\u1ed9t chu k\u00ec l\u00e0: A. 1\/15 (s) B. 1\/30 (s) C. 1\/6 (s) D. 1\/3 (s) TRANG 54","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 99: Con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, \u0111\u1ed9 c\u1ee9ng k=80N\/m, v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m=200g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi bi\u00ean \u0111\u1ed9 A=5(cm), l\u1ea5y g=10m\/s2. Trong m\u1ed9t chu k\u00ec T, th\u1eddi gian l\u00f2 xo d\u00e3n l\u00e0: A. \u03c0\/15 (s) B. \u03c0\/30 (s) C. \u03c0\/12 (s) D. \u03c0\/24 (s) C\u00e2u 100: Treo qu\u1ea3 c\u1ea7u nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1kg v\u00e0o l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m. K\u00edch th\u00edch cho qu\u1ea3 c\u1ea7u dao \u0111\u1ed9ng th\u1eb3ng \u0111\u1ee9ng. L\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=10m\/s2. Bi\u1ebft trong m\u1ed9t chu k\u00ec dao \u0111\u1ed9ng, th\u1eddi gian l\u00f2 xo d\u00e3n g\u1ea5p \u0111\u00f4i th\u1eddi gian l\u00f2 xo n\u00e9n. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a qu\u1ea3 c\u1ea7u l\u00e0: A. 10cm B. 30cm C. 20cm D. 15cm C\u00e2u 101: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m v\u1eadt nh\u1ecf m=250g treo ph\u00eda d\u01b0\u1edbi m\u1ed9t l\u00f2 xo nh\u1eb9 c\u00f3 k=100N\/m. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, k\u00e9o v\u1eadt xu\u1ed1ng d\u01b0\u1edbi m\u1ed9t \u0111o\u1ea1n sao cho l\u00f2 xo gi\u00e3n 7,5cm v\u00e0 th\u1ea3 nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. T\u1ef7 s\u1ed1 gi\u1eefa th\u1eddi gian l\u00f2 xo gi\u00e3n v\u00e0 l\u00f2 xo n\u00e9n trong m\u1ed9t chu k\u00ec dao \u0111\u1ed9ng l\u00e0: A. 0,5 B. 2 C. 3 D. 3,14 C\u00e2u 102: Con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u1ebfn \u0111\u1ed9 8cm. L\u1ea5y g=\u03c02=10 m\/s2. Bi\u1ebft trong m\u1ed9t chu k\u00ec dao \u0111\u1ed9ng th\u1eddi gian l\u00f2 xo b\u1ecb gi\u00e3n g\u1ea5p \u0111\u00f4i th\u1eddi gian l\u00f2 xo b\u1ecb n\u00e9n. Th\u1eddi gian l\u00f2 xo b\u1ecb gi\u00e3n trong m\u1ed9t chu k\u00ec l\u00e0: A. 4\/15s B. 2\/15s C. 0,2s D. 0,3s C\u00e2u 103: M\u1ed9t CLLX treo th\u1eb3ng \u0111\u1ee9ng c\u00f3 chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a l\u00f2 xo l\u00e0 30cm v\u00e0 khi v\u1eadt \u1edf VTCB chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo l\u00e0 31cm, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi bi\u00ean \u0111\u1ed9 A. L\u1ea5y g=\u03c02=10 m\/s2. Trong m\u1ed9t chu k\u00ec, th\u1eddi gian l\u00f2 xo n\u00e9n l\u00e0 0,05s. T\u00ednh A A. 3 cm B. 1cm C. 2 cm D. 2cm C\u00e2u 104: Con l\u1eafc l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=100 N\/m treo v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 250g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Bi\u1ebft r\u1eb1ng trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng th\u1eddi gian l\u00f2 xo b\u1ecb gi\u00e3n trong m\u1ed9t chu k\u00ec l\u00e0 5\uf070 s. L\u1ea5y g=\u03c02=10 m\/s2. 60 Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 5cm B. 5 3 cm C. 5 3 cm D. 5 3 cm 3 2 C\u00e2u 105: (VDC-\u0110H 2016) M\u1ed9t CLLX treo v\u00e0o m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00e0o theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. T\u1ea1i th\u1eddi \u0111i\u1ec3m l\u00f2 xo d\u00e3n 2cm, t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0 4 5 v (cm\/s); t\u1ea1i th\u1eddi \u0111i\u1ec3m l\u00f2 xo d\u00e3n 4cm, t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0 6 2 v (cm\/s); t\u1ea1i th\u1eddi \u0111i\u1ec3m l\u00f2 xo d\u00e3n 6cm, t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0 3 6 v (cm\/s). L\u1ea5y g=9,8 m\/s2. Trong m\u1ed9t chu k\u00ec, t\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a v\u1eadt trong kho\u1ea3ng th\u1eddi gian l\u00f2 xo d\u00e3n c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y: A. 1,26 m\/s B. 1.43 m\/s C. 1,21 m\/s D. 1,52 m\/s C\u00e2u 106: (VDC) M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 d\u1ecdc theo tr\u1ee5c Ox v\u1edbi bi\u00ean \u0111\u1ed9 3cm. X\u00e9t chuy\u1ec3n \u0111\u1ed9ng theo m\u1ed9t chi\u1ec1u t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng O \u0111\u1ebfn bi\u00ean. Khi \u0111\u00f3, t\u1ed1c \u0111\u1ed9 trung b\u00ecnh khi v\u1eadt \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng \u0111\u1ebfn v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 x0 b\u1eb1ng t\u1ed1c \u0111\u1ed9 trung b\u00ecnh khi v\u1eadt \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 x0 \u0111\u1ebfn bi\u00ean v\u00e0 c\u00f9ng b\u1eb1ng 60 cm\/s. L\u1ea5y g = \u03c02 (m\/s2). Trong m\u1ed9t chu k\u00ec, kho\u1ea3ng th\u1eddi gian l\u00f2 xo b\u1ecb d\u00e3n x\u1ea5p x\u1ec9 l\u00e0 A. 0,12s B. 0,05s C. 0,15s D. 0,08s TRANG 55","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 D\u1ea0NG 5: L\u1ef0C K\u00c9O V\u1ec0 - L\u1ef0C \u0110\u00c0N H\u1ed2I L\u1ef0C K\u00c9O V\u1ec0 L\u1ef0C \u0110\u00c0N H\u1ed2I (F\u0111h) (PH\u1ee4C H\u1ed2I) F\u0111h= K. \u2212 o =K. ox \u2756 Bi\u1ec3u th\u1ee9c: F= -K.x A < \u2206lo A > \u2206lo \u2756 \u0110\u1ed9 l\u1edbn: F = K.x \u2756 L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i: \u2756 L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i (l\u1ef1c k\u00e9o c\u1ef1c \u0111\u1ea1i) + Fmax=K.A: t\u1ea1i VTB F\u0111hmax= K.( A + \u2206lo) F\u0111h k\u00e9o max= K.( A + \u2206lo) + Fmin=0: t\u1ea1i VTCB \u2756 \u0110\u1ed1i v\u1edbi CLLX n\u1eb1m ngang \u2756 L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c ti\u1ec3u: \u2756 L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c ti\u1ec3u: th\u00ec l\u1ef1c ph\u1ee5c h\u1ed3i ch\u00ednh l\u00e0 l\u1ef1c \u0111\u00e0n F\u0111hmin= K.(\u2206lo -A ) F\u0111hmin=0 (t\u1ea1i v\u1ecb tr\u00ed chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean) h\u1ed3i. \u2756 L\u1ef1c \u0111\u00e0n h\u1ed3i n\u00e9n c\u1ef1c \u0111\u1ea1i(l\u1ef1c \u0111\u1ea9y \u0111\u00e0n \u2756 T\u1ec9 s\u1ed1: h\u1ed3i): F\u00f1hmax oA F\u0111h n\u00e9n max = K.( A - \u2206lo) F\u00f1hmin oA C\u00e2u 107: Ch\u1ecdn \u0111\u00e1p \u00e1n sai.Trong dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a ch\u1ea5t \u0111i\u1ec3m l\u1ef1c k\u00e9o v\u1ec1: A. Ng\u01b0\u1ee3c pha v\u1edbi li \u0111\u1ed9. B. Vu\u00f4ng pha v\u1edbi v\u1eadn t\u1ed1c. C. Ng\u01b0\u1ee3c pha v\u1edbi gia t\u1ed1c. D. Lu\u00f4n h\u01b0\u1edbng v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng C\u00e2u 108: (\u0110H-2017) M\u1ed9t con l\u1eafc l\u00f2 xo \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. L\u1ef1c k\u00e9o v\u1ec1 t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc c\u00f3 \u0111\u1ed9 l\u1edbn t\u1ec9 l\u00ea thu\u1eadn v\u1edbi A. \u0110\u1ed9 l\u1edbn v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt. B. \u0110\u1ed9 l\u1edbn li \u0111\u1ed9 c\u1ee7a v\u1eadt. C. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc. D. Chi\u1ec1u d\u00e0i l\u00f2 xo c\u1ee7a con l\u1eafc. C\u00e2u 109: (\u0110H-2017) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k, dap \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox quanh v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng O. Bi\u1ec3u th\u1ee9c l\u1ef1c k\u00e9o v\u1ec1 t\u00e1c d\u1ee5ng l\u00ean v\u1eadt theo li \u0111\u1ed9 X l\u00e0: A. F= kx. B. F = -kx. C. F= 1 kx2. D. F= - 1 kx2. 2 2 C\u00e2u 110: (\u0110H-2019) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf v\u00e0 l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng k. Con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox n\u1eb1m ngang. Khi v\u1eadt c\u00f3 li \u0111\u1ed9 x th\u00ec l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ee7a l\u00f2 xo t\u00e1c d\u1ee5ng v\u00e0o n\u00f3 l\u00e0 A. \u2212 1 kx . B. -kx2 C. \u2212 1 kx2 D. \u2013kx 2 2 C\u00e2u 111: M\u1ed9t con l\u1eafc l\u00f2 xo treo v\u00e0o m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi chu k\u1ef3 T v\u00e0 bi\u00ean \u0111\u1ed9 A. Bi\u1ebft r\u1eb1ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u00f2 xo \u0111\u00e3 gi\u00e3n m\u1ed9t \u0111o\u1ea1n \uf044 0 \uf03c A . Trong m\u1ed9t chu k\u00ec, n\u1ebfu kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t gi\u1eefa th\u1eddi \u0111i\u1ec3m l\u1ef1c ph\u1ee5c h\u1ed3i \u0111\u1ed5i chi\u1ec1u \u0111\u1ebfn th\u1eddi \u0111i\u1ec3m l\u1ef1c \u0111\u00e0n h\u1ed3i \u0111\u1ed5i chi\u1ec1u l\u00e0 \uf044t = T th\u00ec m\u1ed7i li\u00ean h\u1ec7 gi\u1eefa \uf044 0 v\u1edbi A l\u00e0 12 A. A = 3\uf044 0 . B. A = 2\uf044 0 . C. A = 4\uf044 0 . D. A = 5\uf044 0 . C\u00e2u 112: Trong dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, l\u1ef1c k\u00e9o v\u1ec1 c\u00f3 gi\u00e1 tr\u1ecb: A. Bi\u1ebfn thi\u00ean tu\u1ea7n ho\u00e0n nh\u01b0ng kh\u00f4ng \u0111i\u1ec1u h\u00f2a. B. Bi\u1ebfn thi\u00ean \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1, ng\u01b0\u1ee3c pha v\u1edbi li \u0111\u1ed9. C. Bi\u1ebfn thi\u00ean \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1, c\u00f9ng pha v\u1edbi li \u0111\u1ed9. D. Bi\u00ean thi\u00ean \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1, c\u00f9ng pha v\u1edbi v\u1eadn t\u1ed1c. C\u00e2u 113: Trong dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, nh\u1eefng \u0111\u1ea1i l\u01b0\u1ee3ng bi\u1ebfn thi\u00ean theo th\u1eddi gian c\u00f9ng t\u1ea7n s\u1ed1 v\u1edbi v\u1eadn t\u1ed1c l\u00e0: A. Li \u0111\u1ed9, gia t\u1ed1c, l\u1ef1c ph\u1ee5c h\u1ed3i B. \u0110\u1ed9ng n\u0103ng, th\u1ebf n\u0103ng, l\u1ef1c ph\u1ee5c h\u1ed3i C. Li \u0111\u1ed9, gia t\u1ed1c v\u00e0 \u0111\u1ed9ng n\u0103ng D. Li \u0111\u1ed9, \u0111\u1ed9ng n\u0103ng v\u00e0 th\u1ebf n\u0103ng TRANG 56","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 114: M\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 1 kg dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x = 10 cos \uf0e6 \uf070t + \uf070 \uf0f6 cm, t \u0111\u01b0\u1ee3c t\u00ednh \uf0e7\uf0e8 2 \uf0f7\uf0f8 b\u1eb1ng gi\u00e2y. L\u1ef1c ph\u1ee5c h\u1ed3i (l\u1ef1c k\u00e9o v\u1ec1) t\u00e1c d\u1ee5ng l\u00ean v\u1eadt v\u00e0o th\u1eddi \u0111i\u1ec3m t = 0,5 s l\u00e0 A. 1 N. B. 0 N. C. 2 N. D. 0,5 N. C\u00e2u 115: Con l\u1eafc l\u00f2 xo c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 0,5 kg \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. \u0110\u1ed9 l\u1edbn c\u1ef1c \u0111\u1ea1i c\u1ee7a gia t\u1ed1c v\u00e0 v\u1eadn t\u1ed1c l\u1ea7n l\u01b0\u1ee3t l\u00e0 5 m\/s2 v\u00e0 0,5 m\/s. Khi t\u1ed1c \u0111\u1ed9 c\u1ee7a con l\u1eafc l\u00e0 0,3 m\/s th\u00ec l\u1ef1c k\u00e9o v\u1ec1 c\u00f3 \u0111\u1ed9 l\u1edbn l\u00e0 A. 1 N. B. 0,2 N. C. 2 N. D. 0,4 N. C\u00e2u 116: M\u1ed9t con l\u1eafc l\u00f2 xo, g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 50 N\/m, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 2 kg, dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 d\u1ecdc theo tr\u1ee5c Ox theo ph\u01b0\u01a1ng ngang (O l\u00e0 v\u1ecb tr\u00ed c\u1ea3n b\u1eb1ng) theo ph\u01b0\u01a1ng tr\u00ecnh x = 6cos(\u03c9t + \u03c0\/3) (cm). T\u00ednh l\u1ef1c \u0111\u00e0n h\u1ed3i l\u00f2 xo \u1edf th\u1eddi \u0111i\u1ec1m t = 0,4\u03c0 (s). A. 150 N. B. 1,5 N. C. 300 N. D. 3,0 N. C\u00e2u 117: M\u1ed9t qu\u1ea3 c\u1ea7u nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1 kg g\u1eafn v\u00e0o \u0111\u1ea7u l\u00f2 xo \u0111\u01b0\u1ee3c k\u00edch th\u00edch dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang v\u1edbi t\u1ea7n s\u1ed1 g\u00f3c 10 rad\/s. Khi t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0 60 cm\/s th\u00ec l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng l\u00ean v\u1eadt b\u1eb1ng 8 N. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. 5 cm. B. 8 cm. C. 10 cm. D. 12 cm. C\u00e2u 118: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, dao \u0111\u1ed9ng gi\u1eefa hai \u0111i\u1ec3m th\u1ea5p nh\u1ea5t v\u00e0 cao nh\u1ea5t c\u00e1ch nhau 8cm. Kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a qu\u1ea3 n\u1eb7ng 150g, k=15N\/m. L\u1ea5y g=10m\/s2. Gi\u00e1 tr\u1ecb c\u1ef1c ti\u1ec3u c\u1ee7a l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng v\u00e0o qu\u1ea3 n\u1eb7ng l\u00e0 A. 2,1N B. 1,5N C. 0,9 N D. 0,6N C\u00e2u 119: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 10cm. L\u1ea5y g=\u03c02=10 m\/s2. T\u1ef7 s\u1ed1 gi\u1eefa l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c ti\u1ec3u v\u00e0 c\u1ef1c \u0111\u1ea1i l\u00e0 3\/7. T\u1ea7n s\u1ed1 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 0,25 Hz B. 0,5 Hz C. 1Hz D. 2Hz C\u00e2u 120: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g. K\u00edch th\u00edch cho con l\u1eafc dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng th\u00ec th\u1ea5y con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 2,5Hz v\u00e0 trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo thay \u0111\u1ed5i t\u1eeb l1=20cm \u0111\u1ebfn l2=24cm. L\u1ea5y g=\u03c02=10 m\/s2. L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i, c\u1ef1c ti\u1ec3u c\u1ee7a l\u00f2 xo l\u1ea7n l\u01b0\u1ee3t l\u00e0: A. 1,5N; 0,5N B. 1,5N; 0N C. 2N; 1,5N D. 2N, 0N C\u00e2u 121: M\u1ed9t con l\u1eafc l\u00f2 xo th\u1eb1ng \u0111\u1ee9ng dao \u0111\u1ed9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x=8cos(10t + \u03c0). L\u1ea5y g=\u03c02=10 m\/s2. Th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ee7a lo xo t\u0103ng t\u1eeb c\u1ef1c ti\u1ec3u \u0111\u1ebfn c\u1ef1c \u0111\u1ea1i l\u00e0: A. \u03c0\/10 s B. \u03c0\/15 s C. \u03c0\/30 s D. 3\u03c0\/10 s C\u00e2u 122: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, m = 100 g, x = 4cos(10t \u2013 2\u03c0\/3) (cm) (chi\u1ec1u d\u01b0\u01a1ng h\u01b0\u1edbng l\u00ean). T\u00ecm F\u0111h v\u00e0 Fhp t\u1ea1i th\u1eddi \u0111i\u1ec3m v\u1eadt \u0111\u00f3 \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng 3 cm? A. Fdh = 0,9 N v\u00e0 Fhp = 0,1 N. B. Fdh = 0,1 N v\u00e0 Fhp = 0,9 N. C. Fdh = 1,2N v\u00e0 Fhp = 0,2 N. D. Fdh = 0,2 N v\u00e0 Fhp = 1,2 N. C\u00e2u 123: G\u1eafn m\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 400g v\u00e0o m\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, khi v\u1eadt c\u00e2n b\u1eb1ng l\u00f2 xo d\u00e3n m\u1ed9t \u0111o\u1ea1n 10cm. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o v\u1eadt xu\u1ed1ng d\u01b0\u1edbi m\u1ed9t \u0111o\u1ea1n 5cm theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng r\u1ed3i bu\u00f4ng tay cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Ch\u1ecdn chi\u1ec1u d\u01b0\u01a1ng c\u1ee7a tr\u1ee5c Ox h\u01b0\u1edbng l\u00ean. K\u1ec3 t\u1eeb l\u00fac th\u1ea3 v\u1eadt \u0111\u1ebfn l\u00fac v\u1eadt \u0111i \u0111\u01b0\u1ee3c m\u1ed9t \u0111o\u1ea1n 7cm th\u00ec l\u00fac \u0111\u00f3 \u0111\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng l\u00ean v\u1eadt l\u00e0 bao nhi\u00eau? L\u1ea5y g=10m\/s2 A. 2,8N B. 2N C. 4,8N D. 3,2N C\u00e2u 124: Con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, l\u00f2 xo c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng kh\u00f4ng \u0111\u00e1ng k\u1ec3. H\u00f2n bi \u0111ang \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec \u0111\u01b0\u1ee3c k\u00e9o xu\u1ed1ng d\u01b0\u1edbi theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t \u0111o\u1ea1n 3cm r\u1ed3i th\u1ea3 nh\u1eb9 cho n\u00f3 dao \u0111\u1ed9ng. H\u00f2n bi th\u1ef1c hi\u1ec7n 50 dao \u0111\u1ed9ng m\u1ea5t 20s. L\u1ea5y g=\u03c02=10 m\/s2. T\u1ef7 s\u1ed1 \u0111\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i v\u00e0 c\u1ef1c ti\u1ec3u c\u1ee7a l\u00f2 xo khi dao \u0111\u1ed9ng l\u00e0: A. 7 B. 5 C. 4 D. 3 TRANG 57","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 125: M\u1ed9t CLLX treo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=100g, ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 l\u00fac v\u1eadt \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 chi\u1ec1u d\u01b0\u01a1ng tr\u1ee5c t\u1ecda \u0111\u1ed9 h\u01b0\u1edbng l\u00ean. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00f2 xo l\u00e0 x=4cos(10t + \u03c0\/3) cm. L\u1ea5y g=\u03c02=10 m\/s2. \u0110\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt l\u00fac v\u1eadt \u0111\u00e3 \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng 3cm t\u00ednh t\u1eeb th\u1eddi \u0111i\u1ec3m t=0 b\u1eb1ng A. 1,1N B. 2N C. 0,9N D. 1,6N C\u00e2u 126: M\u1ed9t CLLX treo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=100g, ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 l\u00fac v\u1eadt \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 chi\u1ec1u d\u01b0\u01a1ng tr\u1ee5c t\u1ecda \u0111\u1ed9 h\u01b0\u1edbng xu\u1ed1ng. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00f2 xo l\u00e0 x=4cos(10t+ \u03c0\/3) cm. L\u1ea5y g=\u03c02=10 m\/s2. \u0110\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt l\u00fac v\u1eadt \u0111\u00e3 \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng 3cm t\u00ednh t\u1eeb th\u1eddi \u0111i\u1ec3m t=0 b\u1eb1ng A. 1,1N B. 2N C. 0,9N D. 1,6N C\u00e2u 127: M\u1ed9t v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u01a1ng m g\u1eafn v\u00e0o m\u1ed9t \u0111\u1ea7u c\u1ee7a l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 2,5Hz. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, chi\u1ec1u d\u00e0i l\u00f2 xo thay \u0111\u1ed5i t\u1eeb l1=20cm \u0111\u1ebfn l2=24cm. L\u1ea5y g=\u03c02=10 m\/s2. \u0110i\u1ec1u n\u00e0o sau \u0111\u00e2y sai? A. Khi v\u1eadt \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, l\u00f2 xo \u0111\u00e3 d\u00e3n 4cm B. Chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a l\u00f2 xo l\u00e0 18cm C. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng l\u00f2 xo lu\u00f4n b\u1ecb d\u00e3n D. L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c ti\u1ec3u c\u1ee7a l\u00f2 xo b\u1eb1ng kh\u00f4ng. C\u00e2u 128: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, g\u1ed3m v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m = 200 g, l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 50 N\/m. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o v\u1eadt xu\u1ed1ng d\u01b0\u1edbi \u0111\u1ec3 l\u00f2 xo gi\u00e3n 12 cm r\u1ed3i th\u1ea3 nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. L\u1ea5y g = 10 = \uf0702 m\/s2. Kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t gi\u1eefa hai l\u1ea7n li\u00ean ti\u1ebfp l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ee7a l\u00f2 xo b\u1eb1ng 0 l\u00e0 A. 1 s. B. 1 s. C. 2 s. D. 4 s. 10 15 15 15 C\u00e2u 129: M\u1ed9t CLLX g\u1ed3m m\u1ed9t v\u1eadt n\u1eb7ng m=100g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi bi\u00ean \u0111\u1ed9 6cm, chu k\u00ec T= \u03c0\/5 (s), g=\u03c02=10 m\/s2. T\u00ednh th\u1eddi gian trong m\u1ed9t chu k\u00ec, l\u1ef1c \u0111\u00e0n h\u1ed3i c\u00f3 \u0111\u1ed9 l\u1edbn kh\u00f4ng nh\u1ecf h\u01a1n 1,3N A. 0,21s B. 0,18s C. 0,15s D. 0,12s C\u00e2u 130: M\u1ed9t CLLX treo th\u1eb3ng \u0111\u1ee9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Chu k\u00ec v\u00e0 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u1ea7n l\u01b0\u1ee3t l\u00e0 0,4s v\u00e0 8cm. Ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 t\u1ea1i v\u1ecb tr\u00ed c\u1ea7n b\u1eb1ng, chi\u1ec1u d\u01b0\u01a1ng h\u01b0\u1edbng xu\u1ed1ng, t\u1ea1i th\u1eddi \u0111i\u1ec3m t=0 v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 x=4cm theo chi\u1ec1u d\u01b0\u01a1ng. L\u1ea5y g= \u03c02=10 m\/s2. Th\u1eddi gian ng\u1eafn nh\u1ea5t k\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m t=0 \u0111\u1ebfn khi l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ee7a l\u00f2 xo c\u00f3 \u0111\u1ed9 l\u1edbn c\u1ef1c ti\u1ec3u l\u00e0: A. 1\/5 (s) B. 7\/30 (s) C. 3\/10 (s) D. 1\/30 (s) C\u00e2u 131: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng v\u1edbi v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g \u0111ang dao \u0111\u1ed9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh: x=4sin(10t \u2013 \u03c0\/6) cm. Ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 O \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, chi\u1ec1u d\u01b0\u01a1ng tr\u1ee5c Ox h\u01b0\u1edbng l\u00ean. L\u1ea5y g=10m\/s2. \u0110\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng v\u00e0o v\u1eadt sau khi v\u1eadt \u0111\u00e3 \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng S=5cm k\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u: A. 1,6N B. 1,2N C. 0,9 N D. 0,7 N C\u00e2u 132: Con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng. Chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a l\u00f2 xo l\u00e0 20cm. Khi v\u1eadt \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec \u0111\u1ed9 d\u00e3n c\u1ee7a l\u00f2 xo l\u00e0 4cm. L\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i v\u00e0 c\u1ef1c ti\u1ec3u l\u1ea7n l\u01b0\u1ee3t l\u00e0 10N v\u00e0 6N. Chi\u1ec1u d\u00e0i c\u1ef1c \u0111\u1ea1i v\u00e0 c\u1ef1c ti\u1ec3u c\u1ee7a l\u00f2 xo trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng l\u00e0: A. 25cm v\u00e0 24cm B. 24cm v\u00e0 23cm C. 26cm v\u00e0 24cm D. 25cm v\u00e0 23cm C\u00e2u 133: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng, \u0111\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo K=50N\/m. Khi v\u1eadt dao \u0111\u1ed9ng th\u00ec l\u1ef1c k\u00e9o c\u1ef1c \u0111\u1ea1i v\u00e0 l\u1ef1c n\u00e9n c\u1ef1c \u0111\u1ea1i c\u1ee7a l\u00f2 xo l\u00ean gi\u00e1 treo l\u1ea7n l\u01b0\u1ee3t l\u00e0 4N v\u00e0 2N. L\u1ea5y g=10m\/s2. V\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt l\u00e0: A. 30 5 cm\/s B. 40 5 cm\/s C. 50 5 cm\/s D. 60 5 cm\/s TRANG 58","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 134: Cho con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng x=2cos10\u03c0t (cm). Bi\u1ebft v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=100g, l\u1ea5y g=\u03c02=10m\/s2. L\u1ef1c \u0111\u1ea9y \u0111\u00e0n h\u1ed3i l\u1edbn nh\u1ea5t c\u1ee7a l\u00f2 xo b\u1eb1ng: A. 0,5N B. 3N C. 1N D. 2N C\u00e2u 135: M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 x = 8cos(10t + \uf070) cm (g\u1ed1c t\u1ecda \u0111\u1ed9 \u0111\u01b0\u1ee3c ch\u1ecdn t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, chi\u1ec1u \u0111\u01b0\u01a1ng h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng xu\u1ed1ng d\u01b0\u1edbi), t \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng gi\u00e2y. L\u1ea5y g = \uf0702 = 10 m\/s2. Th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng l\u00ean v\u1eadt t\u0103ng t\u1eeb c\u1ef1c ti\u1ec3u \u0111\u1ebfn c\u1ef1c \u0111\u1ea1i l\u00e0 A. \uf070 s. B. \uf070 s. C. \uf070 s. D. 3\uf070 s. 10 15 30 10 C\u00e2u 136: (\u0110H\u22122014) M\u1ed9t con l\u1eafc l\u00f2 xo treo v\u00e0o m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi chu k\u00ec 1,2s. Trong m\u1ed9t chu k\u00ec, n\u1ebfu t\u1ef7 s\u1ed1 th\u1eddi gian l\u00f2 xo gi\u00e3n v\u1edbi th\u1eddi gian l\u00f2 xo n\u00e9n b\u1eb1ng 2 th\u00ec th\u1eddi gian m\u00e0 l\u1ef1c \u0111\u00e0n h\u1ed3i ng\u01b0\u1ee3c chi\u1ec1u l\u1ef1c k\u00e9o v\u1ec1 l\u00e0: A. 0,2s B. 0,1s C. 0,3s D. 0,4s C\u00e2u 137: Con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1kg \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T v\u00e0 bi\u00ean \u0111\u1ed9 b\u1eb1ng 4cm. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t gi\u1eefa hai l\u1ea7n \u0111\u1ed9 l\u1edbn l\u1ef1c \u0111\u00e0n h\u1ed3i v\u00e0 k\u00e9o v\u1ec1 b\u1eb1ng nhau l\u00e0 T\/4. L\u1ea5y g=10m\/s2. Ch\u1ecdn g\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. C\u01a1 n\u0103ng c\u1ee7a con l\u1eafc l\u00e0: 2 B. 0,2J C. 0,3J 2 A. J D. J 10 5 C\u00e2u 138: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang v\u1edbi n\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng 1J v\u00e0 l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i l\u00e0 10N. G\u1ecdi J l\u00e0 \u0111\u1ea7u c\u1ed1 \u0111\u1ecbnh c\u1ee7a l\u00f2 xo, kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t gi\u1eefa hai l\u1ea7n li\u00ean ti\u1ebfp \u0111i\u1ec3m J ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c k\u00e9o 5 3 N l\u00e0 0,1s. T\u00ednh qu\u00e3ng \u0111\u01b0\u1eddng l\u1edbn nh\u1ea5t m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c trong 0,7s: A. 100cm B. 40cm C. 64cm D. 60cm C\u00e2u 139: (Chuy\u00ean V\u0129nh Ph\u00fac \u2013 2017) M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m qu\u1ea3 c\u1ea7u nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m = 150 g v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 60 N\/m. Ng\u01b0\u1eddi ta \u0111\u01b0a qu\u1ea3 c\u1ea7u \u0111\u1ebfn v\u1ecb tr\u00ed l\u00f2 xo kh\u00f4ng b\u1ecb bi\u1ebfn d\u1ea1ng r\u1ed3i truy\u1ec1n cho n\u00f3 m\u1ed9t v\u1eadn t\u1ed1c ban \u0111\u1ea7u v0 = 3 m\/s theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng h\u01b0\u1edbng xu\u1ed1ng. 2 Sau khi \u0111\u01b0\u1ee3c truy\u1ec1n v\u1eadn t\u1ed1c con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. G\u1ed1c th\u1eddi gian l\u00e0 l\u00fac qu\u1ea3 c\u1ea7u \u0111\u01b0\u1ee3c truy\u1ec1n v\u1eadn t\u1ed1c, l\u1ea5y g = 10 m\/s2. Th\u1eddi gian ng\u1eafn nh\u1ea5t k\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u \u0111\u1ebfn l\u00fac l\u1ef1c \u0111\u00e0n h\u1ed3i t\u00e1c d\u1ee5ng l\u00ean v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn 3 N l\u00e0 \uf070 \uf070 \uf070 \uf070 A. s. B. s. C. s. D. s. 60 20 30 5 C\u00e2u 140: (CSP-2019) M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a d\u1ecdc theo tr\u1ee5c Ox n\u1eb1m ngang, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 150 g v\u00e0 n\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng 38,4 mJ. T\u1ea1i th\u1eddi \u0111i\u1ec3m v\u1eadt c\u00f3 t\u1ed1c \u0111\u1ed9 16\u03c0 (cm\/s) th\u00ec \u0111\u1ed9 l\u1edbn l\u1ef1c k\u00e9o v\u1ec1 l\u00e0 0,96 N. L\u1ea5y \u03c02=10. \u0110\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo l\u00e0 A. 40 N\/m B. 36 N\/m C. 24 N\/m D. 50 N\/m TRANG 59","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 141: (Chuy\u00ean PBC-2019) M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng \u1edf n\u01a1i c\u00f3 g=10m\/s2. L\u1ea5y \u03c02. B\u1ecf qua m\u1ecdi l\u1ef1c c\u1ea3n. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng n\u00e2ng v\u1eadt nh\u1ecf t\u1edbi v\u1ecb tr\u00ed l\u00f2 xo kh\u00f4ng bi\u1ebfn d\u1ea1ng theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, r\u1ed3i bu\u00f4ng ra \u0111\u1ed3ng th\u1eddi truy\u1ec1n cho n\u00f3 v\u1eadn t\u1ed1c 10\uf070 5 cm\/s h\u01b0\u1edbng v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 2,5Hz. T\u1ef7 s\u1ed1 l\u1ef1c k\u00e9o \u0111\u00e0n h\u1ed3i c\u1ef1c \u0111\u1ea1i t\u00e1c d\u1ee5ng l\u00ean gi\u00e1 treo v\u00e0 l\u1ef1c \u0111\u1ea9y c\u1ef1c \u0111\u1ea1i t\u00e1c d\u1ee5ng l\u00ean gi\u00e1 treo l\u00e0: A. 5 B. 1,67 C. 4 D. 3 C\u00e2u 142: (Minh H\u1ecda-2019) M\u1ed9t con l\u1eafc l\u00f2 xo treo th\u1eb3ng \u0111\u1ee9ng. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, n\u00e2ng v\u1eadt nh\u1ecf theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng l\u00ean \u0111\u1ebfn v\u1ecb tr\u00ed l\u00f2 xo kh\u00f4ng bi\u1ebfn d\u1ea1ng r\u1ed3i truy\u1ec1n cho v\u1eadt v\u1eadn t\u1ed1c 10\u03c0 3 cm\/s h\u01b0\u1edbng v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 5Hz. L\u1ea5y g=10m\/s2; \u03c02=10. Trong m\u1ed9t chu k\u00ec dao \u0111\u1ed9ng, kho\u1ea3ng th\u1eddi gian m\u00e0 l\u1ef1c k\u00e9o v\u1ec1 v\u00e0 l\u1ef1c \u0111\u00e0n h\u1ed3i c\u1ee7a l\u00f2 xo t\u00e1c d\u1ee5ng l\u00ean v\u1eadt ng\u01b0\u1ee3c h\u01b0\u1edbng nhau l\u00e0: A. 1 B. 1 C. 1 s D. 1 s s 6 s 30 12 60 D\u1ea0NG 6: C\u1eaeT- GH\u00c9P L\u00d2 XO \u2756 C\u1eaft l\u00f2 xo: chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo s\u1ebd t\u1ef7 l\u1ec7 ngh\u1ecbch v\u1edbi \u0111\u1ed9 c\u1ee9ng c\u1ee7a n\u00f3\uf0de K1 = 2 K2 1 ' 0 Gh\u00e9p n\u1ed1i ti\u1ebfp Gh\u00e9p song song 1 =1+1 Kss = K1 + K2 Knt K1 K2 1 =1+1 Tnt2 =T12 + T22 Tss2 T12 T22 1 =1+1 f nt 2 = f12 + f 2 fnt2 f12 f22 2 C\u00e2u 143: M\u1ed9t l\u00f2 xo d\u00e0i 1,2m \u0111\u1ed9 c\u1ee9ng 120N\/m. Khi c\u1eaft l\u00f2 xo th\u00e0nh 2 l\u00f2 xo c\u00f3 chi\u1ec1u d\u00e0i 100cm v\u00e0 20cm th\u00ec \u0111\u1ed9 c\u1ee9ng t\u01b0\u01a1ng \u1ee9ng l\u1ea7n l\u01b0\u1ee3t l\u00e0: A. 144N\/m v\u00e0 720N\/m B. 720N\/m v\u00e0 144N\/m C. 100N\/m v\u00e0 20N\/m D. 20N\/m v\u00e0 100N\/m C\u00e2u 144: Con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt n\u1eb7ng treo d\u01b0\u1edbi l\u00f2 xo, c\u00f3 chu k\u00ec dao \u0111\u1ed9ng l\u00e0 T. N\u1ebfu l\u00f2 xo b\u1ecb c\u1eaft b\u1edbt 2\/3 chi\u1ec1u d\u00e0i th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc m\u1edbi l\u00e0: A. 3T B. 0,5T 6 C. T\/3 D. T\/ 3 C\u00e2u 145: M\u1ed9t l\u00f2 xo c\u00f3 chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean 10cm, kh\u1ed1i l\u01b0\u1ee3ng kh\u00f4ng \u0111\u00e1ng k\u1ec3, \u0111\u1eb7t tr\u00ean m\u1eb7t ph\u1eb3ng ngang. Hai v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m1=30g v\u00e0 m2=50g g\u1eafn l\u1ea7n l\u01b0\u1ee3t v\u00e0o hai \u0111\u1ea7u A v\u00e0 B c\u1ee7a l\u00f2 xo. Gi\u1eef c\u1ed1 \u0111\u1ecbnh 1 \u0111i\u1ec3m C n\u1eb1m trong kho\u1ea3ng gi\u1eefa l\u00f2 xo v\u00e0 cho 2 v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng ngang th\u00ec th\u1ea5y chu k\u00ec dao \u0111\u1ed9ng 2 v\u1eadt b\u1eb1ng nhau. Kho\u1ea3ng c\u00e1ch AC l\u00e0: A. 4cm B. 3,75cm C. 6,25cm D. 6cm TRANG 60","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 146: Khi treo v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m l\u1ea7n l\u01b0\u1ee3t v\u00e0o c\u00e1c l\u00f2 xo 1 v\u00e0 2 th\u00ec t\u1ea7n s\u1ed1 dao \u0111\u1ed9ng c\u1ee7a c\u00e1c con l\u1eafc l\u00f2 xo t\u01b0\u01a1ng \u1ee9ng l\u00e0 3Hz v\u00e0 4Hz. N\u1ed1i 2 l\u00f2 xo v\u1edbi nhau th\u00e0nh m\u1ed9t l\u00f2 xo r\u1ed3i treo v\u1eadt n\u1eb7ng m th\u00ec t\u1ea7n s\u1ed1 dao \u0111\u1ed9ng l\u00e0: A. 5,0Hz B. 2,2Hz C. 2,3Hz D. 2,4Hz C\u00e2u 147: M\u1ed9t con l\u1eafc l\u00f2 xo c\u00f3 chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean lo, \u0111\u1ed9 c\u1ee9ng k, v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng m, c\u00f3 chu k\u00ec 2s. N\u1ebfu c\u1eaft b\u1edbt l\u00f2 xo \u0111i 20cm r\u1ed3i cho con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a th\u00ec chu k\u00ec c\u1ee7a n\u00f3 l\u00e0 4 5 s . H\u1ecfi n\u1ebfu c\u1eaft 5 b\u1edbt l\u00f2 xo \u0111i 40cm r\u1ed3i cho con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a th\u00ec chu k\u00ec c\u1ee7a n\u00f3 l\u00e0 bao nhi\u00eau: A. 1s B. 1,41s C. 0,85s D. 1,55s C\u00e2u 148: M\u1ed9t v\u1eadt m g\u1eafn v\u1edbi m\u1ed9t l\u00f2 xo th\u00ec n\u00f3 dao \u0111\u1ed9ng v\u1edbi chu k\u00ec 2s. C\u1eaft l\u00f2 xo n\u00e0y ra l\u00e0m hai ph\u1ea7n b\u1eb1ng nhau r\u1ed3i m\u1eafc song song v\u00e0 treo v\u1eadt v\u00e0o th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 0,5s B. 1s C. 2s D. 4s D\u1ea0NG 7: B\u00c0I TO\u00c1N GI\u1eee C\u1ed0 \u0110\u1ecaNH 1 \u0110I\u1ec2M TR\u00caN L\u00d2 XO TRONG QU\u00c1 TR\u00ccNH DAO \u0110\u1ed8NG (V\u1eacN D\u1ee4NG CAO) \u2756 B\u00e0i to\u00e1n: M\u1ed9t con l\u1eafc l\u00f2 xo n\u1eb1m ngang \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 A \u0111\u1ebfn m\u1ed9t v\u1ecb tr\u00ed n\u00e0o \u0111\u00f3 th\u00ec ng\u01b0\u1eddi ta gi\u1eef c\u1ed1 \u0111\u1ecbnh m\u1ed9t \u0111i\u1ec3m tr\u00ean tr\u1ee5c c\u1ee7a l\u00f2 xo. X\u00e1c \u0111\u1ecbnh bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt sau \u0111\u00f3. \u2756 Ph\u00e2n t\u00edch: \uf08c T\u1ea1i v\u1ecb tr\u00ed ta gi\u1eef c\u1ed1 \u0111\u1ecbnh v\u00ec v\u1eadn t\u1ed1c t\u1ee9c th\u1eddi c\u1ee7a v\u1eadt ch\u01b0a k\u1ecbp thay \u0111\u1ed5i. \uf08d Do chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo b\u1ecb ng\u1eafn \u0111i n\u00ean th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed \u0111\u00f3 s\u1ebd b\u1ecb thay \u0111\u1ed5i so v\u1edbi ban \u0111\u1ea7u. \uf08e \u0110\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo c\u0169ng b\u1ecb thay \u0111\u1ed5i do chi\u1ec1u d\u00e0i l\u00f2 xo b\u1ecb ng\u1eafn \u2756 L\u00e0 m\u1ed9t d\u1ea1ng v\u1eadn dung cao c\u1ee7a ch\u01b0\u01a1ng C\u01a1 h\u1ecdc, nh\u01b0ng kh\u00f3 \u0111\u00e3 c\u00f3 c\u00f4ng th\u1ee9c \u0110\u1ed8C \u0111\u1ec3 x\u1eed l\u00fd g\u1ecdn b\u00e0i to\u00e1n: As2 = \uf0e6\uf0e7\uf0e81\u2212 1 \uf0f6 . \uf0e6 A 2 \u2212 1 x 2 \uf0f6 n \uf0f7\uf0f8 \uf0e7\uf0e8 n \uf0f7\uf0f8 t - Trong \u0111\u00f3: As: l\u00e0 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc sau khi l\u00f2 xo b\u1ecb gi\u1eef. At: l\u00e0 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng l\u00fac \u0111\u1ea7u c\u1ee7a con l\u1eafc. 1= lost ( llost: chi\u1ec1u d\u00e0i l\u00f2 xo b\u1ecb m\u1ea5t \u0111i, lo: chi\u1ec1u d\u00e0i lo xo ban \u0111\u1ea7u). n o x: l\u00e0 li \u0111\u1ed9 c\u1ee7a v\u1eadt t\u1ea1i th\u1eddi \u0111i\u1ec3m gi\u1eef l\u00f2 xo. C\u00e2u 149: Con l\u1eafc l\u00f2 xo n\u1eb1m ngang m\u1ed9t \u0111\u1ea7u c\u1ed1 \u0111\u1ecbnh, m\u1ed9t \u0111\u1ea7u g\u1eafn v\u1edbi v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 A. Khi v\u1eadt n\u1eb7ng chuy\u1ec3n \u0111\u1ed9ng qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec gi\u1eef c\u1ed1 \u0111\u1ecbnh \u0111i\u1ec3m c\u00e1ch \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh m\u1ed9t \u0111o\u1ea1n b\u1eb1ng 1\/4 chi\u1ec1u d\u00e0i t\u1ef1 nhi\u00ean c\u1ee7a l\u00f2 xo. V\u1eadt s\u1ebd ti\u1ebfp t\u1ee5c dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9: A. A B. 0,5A 3 C. A\/2 D. A 2 2 C\u00e2u 150: M\u1ed9t con l\u1eafc l\u00f2 xo \u0111\u01b0\u1ee3c \u0111\u1eb7t n\u1eb1m ngang g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k v\u00e0 v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o v\u1eadt ra m\u1ed9t \u0111o\u1ea1n A r\u1ed3i th\u1ea3 nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0. Khi \u0111\u1ed9ng n\u0103ng b\u1eb1ng th\u1ebf n\u0103ng v\u00e0 l\u00f2 xo d\u00e3n th\u00ec gi\u1eef \u0111\u1ed9t ng\u1ed9t \u0111i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a l\u00f2 xo. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt sau khi gi\u1eef l\u00f2 xo l\u00e0 A. 0,5 A 3 cm. B. A\/2. C. 0,75A. D. 0,25 A 6 . C\u00e2u 151: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng ng\u01b0\u1eddi ta k\u00e9o v\u1eadt ra 8cm r\u1ed3i th\u1ea3 nh\u1eb9, khi v\u1eadt c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 4 cm th\u00ec ng\u01b0\u1eddi ta gi\u1eef c\u1ed1 \u0111\u1ecbnh \u0111i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a l\u00f2 xo. T\u00ednh bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng m\u1edbi c\u1ee7a v\u1eadt: A. 4 2 cm B. 4cm C. 6,3cm D. 2 7 cm TRANG 61","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 152: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean m\u1eb7t ph\u1eb3ng ngang g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 100 N\/m v\u00e0 m=0,1 kg. Khi t=0 v\u1eadt qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u1edbi t\u1ed1c \u0111\u1ed9 v=40\u03c0 cm\/s. \u0110\u1ebfn th\u1eddi \u0111i\u1ec3m t=1\/30s ng\u01b0\u1eddi ta gi\u1eef c\u1ed1 \u0111\u1ecbnh \u0111i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a l\u00f2 xo. T\u00ednh bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng m\u1edbi c\u1ee7a v\u1eadt A. 5 cm B. 4cm C. 2cm D. 2 2 cm C\u00e2u 153: M\u1ed9t con l\u1eafc l\u00f2 xo \u0111\u01b0\u1ee3c \u0111\u1eb7t n\u1eb1m ngang g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k = 40 N\/m v\u00e0 v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m = 400 g. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u00e9o v\u1eadt ra m\u1ed9t \u0111o\u1ea1n 8 cm r\u1ed3i th\u1ea3 nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0. Sau khi th\u1ea3 v\u1eadt t = 7\u03c0\/3 s th\u00ec gi\u1eef \u0111\u1ed9t ng\u1ed9t \u0111i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a l\u00f2 xo khi \u0111\u00f3. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt sau khi gi\u1eef l\u00f2 xo l\u00e0? A. 4 3cm. B. 1,5cm C. 4cm D. 2 7cm. C\u00e2u 154: M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean m\u1eb7t ph\u1eb3ng ngang. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng ng\u01b0\u1eddi ta k\u00e9o v\u1eadt ra 8cm r\u1ed3i th\u1ea3 nh\u1eb9, khi v\u1eadt c\u00e1ch v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 4cm th\u00ec ng\u01b0\u1eddi ta gi\u1eef c\u1ed1 \u0111\u1ecbnh m\u1ed9t ph\u1ea7n ba chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo. T\u00ednh bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng m\u1edbi c\u1ee7a v\u1eadt A. 22 cm B. 4cm C. 6,25 cm D. 2 7 cm C\u00e2u 155: M\u1ed9t l\u00f2 xo nh\u1eb9 n\u1eb1m ngang c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m, m\u1ed9t \u0111\u1ea7u g\u1eafn v\u00e0o \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh I, \u0111\u1ea7u k\u00eca g\u1eafn v\u1edbi v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, k\u00e9o v\u1eadt \u0111\u1ebfn v\u1ecb tr\u00ed l\u00f2 xo d\u00e3n 5cm r\u1ed3i bu\u00f4ng tay cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. B\u1ecf qua ma s\u00e1t, l\u1ea5y \u03c02=10. Khi v\u1eadt \u1edf li \u0111\u1ed9 2,5cm, ng\u01b0\u1eddi ta \u0111\u1ed9t ng\u1ed9t gi\u1eef ch\u1eb7t l\u00f2 xo t\u1ea1i \u0111i\u1ec3m c\u00e1ch I m\u1ed9t \u0111o\u1ea1n b\u1eb1ng 3\/4 chi\u1ec1u d\u00e0i c\u1ee7a l\u00f2 xo khi \u0111\u00f3. H\u1ecfi sau \u0111\u00f3 v\u1eadt ti\u1ebfp t\u1ee5c dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 b\u1eb1ng bao nhi\u00eau A. 5cm B. 3,25cm C. 2,5cm D. 2,25cm C\u00e2u 156: (Minh H\u1ecda-2017) M\u1ed9t CLLX \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 5cm v\u00e0 chu k\u00ec 0,5s tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. Khi v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc c\u00f3 v\u1eadn t\u1ed1c v th\u00ec ng\u01b0\u1eddi ta gi\u1eefa ch\u1eb7t m\u1ed9t \u0111i\u1ec1u tr\u00ean l\u00f2 xo, v\u1eadt ti\u1ebfp t\u1ee5c dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 2,25cm v\u00e0 chu k\u00ec 0,25s. Gi\u00e1 tr\u1ecb c\u1ee7a v g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o: A. 50cm\/s B. 60cm\/s C. 70 cm\/s D. 40cm\/s TRANG 62","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 CH\u1ee6 \u0110\u1ec0 2: CON L\u1eaeC L\u00d2 XO CHUY\u00caN \u0110\u1ec0 \u0110\u1ed2 TH\u1eca D\u1ea0NG 8: \u0110\u1ed2 TH\u1eca DAO \u0110\u1ed8NG C\u1ee6A \u0110\u1ed8NG N\u0102NG - TH\u1ebe N\u0102NG PH\u01af\u01a0NG PH\u00c1P 1. \u0110\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng - th\u1ebf n\u0103ng theo th\u1eddi gian \uf0b5 \u0110\u1eb7c \u0111i\u1ec3m v\u1ec1 \u0111\u1ed3 th\u1ecb: \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026........................... \u2756 B\u01b0\u1edbc 1: Nh\u00ecn v\u00e0o \u2026\u2026\u2026...\u2026 c\u1ee7a \u0111\u1ed3 th\u1ecb \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u2026\u2026\u2026\u2026\u2026\u2026\u2026 \u2756 B\u01b0\u1edbc 2: Nh\u00ecn v\u00e0o l\u00fac v\u1ecb tr\u00ed b\u1eaft \u0111\u1ea7u c\u1ee7a \u0111\u1ed3 th\u1ecb (t=0) \u0111\u1ec3: \u2794 X\u00e1c \u0111\u1ecbnh\u2026\u2026\u2026\u2026\u2026\u2026. \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026.. \u2794 Nh\u00ecn xem xu h\u01b0\u1edbng\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026. \u2794 N\u1ebfu \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026. \u2794 N\u1ebfu\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026.. \u2756 B\u01b0\u1edbc 3: Nh\u00ecn v\u00e0o tr\u1ee5c th\u1eddi gian \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026. \u2794NOTE: 2. \u0110\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng - th\u1ebf n\u0103ng theo li \u0111\u1ed9 - \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n m\u1ed7i quan h\u1ec7 gi\u1eefa \u0111\u1ed9ng n\u0103ng theo li \u0111\u1ed9 x l\u00e0:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 -Khi \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng \u0111\u1ebfn v\u1ecb tr\u00ed bi\u00ean:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026... \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 -Khi \u0111i t\u1eeb v\u1ecb tr\u00ed bi\u00ean \u0111\u1ebfn v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 - \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n m\u1ed7i quan h\u1ec7 gi\u1eefa \u0111\u1ed9ng n\u0103ng theo li \u0111\u1ed9 x l\u00e0:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 -Khi \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng \u0111\u1ebfn v\u1ecb tr\u00ed bi\u00ean:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026... \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 -Khi \u0111i t\u1eeb v\u1ecb tr\u00ed bi\u00ean \u0111\u1ebfn v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng:\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 \u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026\u2026 TRANG 63","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 \uf0b5 B\u00c0I T\u1eacP T\u1ea0I L\u1edaP ( KH\u00d4NG L\u00c0M TR\u01af\u1edaC ) \uf034 V\u00ed D\u1ee5 1 : M\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng m = 500g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 \u0111\u1ed3 th\u1ecb th\u1ebf n\u0103ng \u2013 th\u1eddi gian \u0111\u01b0\u1ee3c cho nh\u01b0 h\u00ecnh v\u1ebd. L\u1ea5y \uf0702 = 10 . Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt A. 4 cm. B. 2 cm. C. 3 cm. D. 10 cm. \uf034 V\u00ed D\u1ee5 2 : M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 \u0111\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng \u2013 th\u1eddi gian \u0111\u01b0\u1ee3c cho nh\u01b0 h\u00ecnh v\u1ebd. Bi\u1ebft r\u1eb1ng, t\u1ea1i th\u1eddi \u0111i\u1ec3m t = 0 v\u1eadt \u0111ang chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u d\u01b0\u01a1ng, pha ban \u0111\u1ea7u c\u1ee7a dao \u0111\u1ed9ng l\u00e0 \uf070 B. \u2212 \uf070 . A. . 3 2 C. \u2212 2\uf070 . D. \uf070 . 3 12 \uf034 V\u00ed D\u1ee5 3 : M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 400 g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi th\u1ebf n\u0103ng ph\u1ee5 thu\u1ed9c theo th\u1eddi gian \u0111\u01b0\u1ee3c cho nh\u01b0 h\u00ecnh v\u1ebd \u2013 g\u1ed1c th\u1ebf n\u0103ng \u0111\u01b0\u1ee3c ch\u1ecdn t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. T\u1ea1i th\u1eddi \u0111i\u1ec3m t = 0, v\u1eadt chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u \u00e2m, l\u1ea5y \uf0702 = 10 . Vi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt ? TRANG 64","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 \uf034 V\u00ed D\u1ee5 4: (S\u1edf HCM \u2013 2017) M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 800 g dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 c\u00f3 \u0111\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng nh\u01b0 h\u00ecnh v\u1ebd. T\u1ea1i th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt \u0111ang chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u d\u01b0\u01a1ng, l\u1ea5y \uf0702 = 10 . Vi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt \uf034 V\u00ed D\u1ee5 5: (Hu\u1ef3nh Th\u00fac Kh\u00e1ng \u2013 2017)M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 250 g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, ch\u1ecdn g\u1ed1c t\u00ednh th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, \u0111\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng theo th\u1eddi gian nh\u01b0 h\u00ecnh v\u1ebd. Th\u1eddi \u0111i\u1ec3m \u0111\u1ea7u ti\u00ean v\u1eadt c\u00f3 v\u1eadn t\u1ed1c th\u00f5a m\u00e3n v = -10 x ( x l\u00e0 li \u0111\u1ed9) l\u00e0 A. 7\uf070 s. \uf070 120 B. s. 30 C. \uf070 s. D. \uf070 s. 20 24 TRANG 65","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 \uf034 V\u00ed D\u1ee5 6: (\u0110H \u2013 2017) M\u1ed9t con l\u1eafc l\u00f2 xo \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. H\u00ecnh b\u00ean l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a \u0111\u1ed9ng n\u0103ng W\u0111 c\u1ee7a con l\u1eafc theo th\u1eddi gian t. Hi\u1ec7u t2 \u2013 t1 c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y? A. 0,27 s. B. 0,24 s. C. 0,22 s. D. 0,20 s. \uf034 V\u00ed D\u1ee5 7: (S\u1edf B\u00ecnh Ph\u01b0\u1edbc \u2013 2017) Hai ch\u1ea5t \u0111i\u1ec3m c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 m1, m2 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1. \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n \u0111\u1ed9ng n\u0103ng c\u1ee7a m1 v\u00e0 th\u1ebf n\u0103ng c\u1ee7a m2 theo li \u0111\u1ed9 nh\u01b0 h\u00ecnh v\u1ebd. T\u1ec9 s\u1ed1 m1 l\u00e0: m2 A. 2 . B. 9 . 3 4 C. 4 . D. 3 . 9 2 TRANG 66","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 \uf034 V\u00ed D\u1ee5 8: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 g\u1ed1c th\u1ebf n\u0103ng \u0111\u01b0\u1ee3c ch\u1ecdn t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. \u0110\u1ed3 th\u1ecb th\u1ebf n\u0103ng \u2013 li \u0111\u1ed9 c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 nh\u01b0 h\u00ecnh v\u1ebd. Gi\u00e1 tr\u1ecb c\u1ee7a x1 l\u00e0 \uf034 V\u00ed D\u1ee5 9: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 5Hz, g\u1ed1c th\u1ebf n\u0103ng \u0111\u01b0\u1ee3c ch\u1ecdn t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. \u0110\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng \u2013 li \u0111\u1ed9 c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c m\u1ed5 t\u1ea3 nh\u01b0 h\u00ecnh v\u1ebd. T\u00ednh t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt khi \u0111\u1ed9ng n\u0103ng c\u00f3 gi\u00e1 tr\u1ecb W\u01111 TRANG 67","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 \uf0b5 B\u00c0I T\u1eacP T\u1ef0 LUY\u1ec6N C\u00e2u 1: (Chuy\u00ean KHTN \u2013 2018) \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 bi\u1ebfn thi\u00ean \u0111\u1ed9ng n\u0103ng c\u1ee7a m\u1ed9t v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a cho \u1edf h\u00ecnh v\u1ebd b\u00ean. Bi\u1ebft v\u1eadt n\u1eb7ng 200 g. L\u1ea5y \uf0702 = 10 . Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. x = 4cos\uf0e6\uf0e7\uf0e8 4\uf070t \u2212 3\uf070 \uf0f6 cm. B. x = 4 cos \uf0e6 4\uf070t \u2212 \uf070 \uf0f6 cm. 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 C. x = 5cos\uf0e6\uf0e7\uf0e8 4\uf070t \u2212 \uf070 \uf0f6 cm. D. x = 5 cos \uf0e6 4\uf070t \u2212 3\uf070 \uf0f6 cm. 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 C\u00e2u 2: M\u1ed9t v\u1eadt nh\u1ecf \u0111\u01b0\u1ee3c g\u1eafn v\u00e0o con l\u1eafc l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng b\u1eb1ng 40 N\/m. K\u00edch th\u00edch cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a quanh m\u1ed9t v\u1ecb tr\u00ed th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 nh\u01b0 \u0111\u1ed3 th\u1ecb. Bi\u1ebft th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u \u00e2m. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. x = 20 cos \uf0e6 2\uf070t + \uf070\uf0f6 cm. B. x = 20 cos \uf0e6 9\uf070 t + \uf070 \uf0f6 cm. \uf0e7\uf0e8 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 4 \uf0f7\uf0f8 C. x = 20 cos \uf0e6 2\uf070t + 3\uf070 \uf0f6 cm. D. x = 20 cos \uf0e6\uf0e7\uf0e8 9\uf070 t + 3\uf070 \uf0f6 cm. \uf0e7\uf0e8 4 \uf0f7\uf0f8 4 4 \uf0f7\uf0f8 C\u00e2u 3: (Nguy\u1ec5n Khuy\u1ebfn \u2013 2018) M\u1ed9t ch\u1ea5t \u0111i\u1ec3m c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m =50g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 \u0111\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng theo th\u1eddi gian c\u1ee7a ch\u1ea5t \u0111i\u1ec3m nh\u01b0 h\u00ecnh b\u00ean. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a ch\u1ea5t \u0111i\u1ec3m g\u1ea7n nh\u1ea5t gi\u00e1 tr\u1ecb n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? A. 2,5 cm. B. 2,0 cm. C. 3,5 cm. D. 1,5 cm. C\u00e2u 4: \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n \u0111\u1ed9ng n\u0103ng c\u1ee7a m\u1ed9t v\u1eadt m = 200 g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a \u1edf h\u00ecnh v\u1ebd b\u00ean \u1ee9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng n\u00e0o sau \u0111\u00e2y (Ch\u1ecdn c\u00e1c ph\u01b0\u01a1ng \u00e1n \u0111\u00fang)? A. x = 5cos\uf0e6\uf0e7\uf0e8 4\uf070t \u2212 3\uf070 \uf0f6 (cm). B. x = 4 cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6\uf0f7\uf0f8(cm ). 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 C. x = 4cos\uf0e6\uf0e7\uf0e8 4\uf070t \u2212 3\uf070 \uf0f6 (cm). D. x = 5 cos \uf0e6 4\uf070t + \uf070 \uf0f6\uf0f7\uf0f8(cm). 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 C\u00e2u 5: M\u00f4t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 400 g dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 c\u00f3 \u0111\u1ed3 th\u1ecb \u0111\u1ed9ng n\u0103ng nh\u01b0 h\u00ecnh v\u1ebd. T\u1ea1i th\u1eddi \u0111i\u1ec3m t = 0 v\u1eadt \u0111ang chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u d\u01b0\u01a1ng, l\u1ea5y \u03c02 =10. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt A. x = 10cos \uf0e6 \uf070t + \uf070\uf0f6 cm B. x = 5cos\uf0e6\uf0e7\uf0e8 2\uf070t \u2212 5\uf070 \uf0f6 cm \uf0e7\uf0e8 6 \uf0f7\uf0f8 6 \uf0f7\uf0f8 C. x = 10cos \uf0e6 \uf070t \u2212 \uf070\uf0f6 cm D. x = 5cos \uf0e6 2\uf070t \u2212 \uf070\uf0f6 cm \uf0e7\uf0e8 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 TRANG 68","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 C\u00e2u 6: (Chuy\u00ean S\u01b0 Ph\u1ea1m H\u00e0 N\u1ed9i \u2013 2018) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo C\u00e2u 7: v\u00e0 v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m = 200g dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u1ea3. Ch\u1ecdn g\u1ed1c C\u00e2u 8: to\u1ea1 \u0111\u1ed9 O t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. S\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a th\u1ebf n\u0103ng c\u1ee7a con l\u1eafc theo th\u1eddi gian \u0111\u01b0\u1ee3c cho nh\u01b0 tr\u00ean \u0111\u1ed3 th\u1ecb. L\u1ea5y \u03c02 =10. Bi\u00ean \u0111\u1ed9 dao C\u00e2u 9: \u0111\u1ed9ng c\u1ee7a con l\u1eafc b\u1eb1ng A. 10 cm. B. 6 cm. C. 4 cm. D. 5 cm. \u0110\u1ed9ng n\u0103ng dao \u0111\u1ed9ng c\u1ee7a m\u1ed9t con l\u1eafc l\u00f2 xo \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 theo th\u1ebf n\u0103ng dao \u0111\u1ed9ng c\u1ee7a n\u00f3 b\u1eb1ng \u0111\u1ed3 th\u1ecb nh\u01b0 h\u00ecnh v\u1ebd. Cho bi\u1ebft kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt b\u1eb1ng 100 g, v\u1eadt dao \u0111\u1ed9ng gi\u1eefa hai v\u1ecb tr\u00ed c\u00e1ch nhau 8 cm. T\u1ea7n s\u1ed1 g\u00f3c c\u1ee7a dao \u0111\u1ed9ng A. 5rad.s\u22121 B. 5 2rad.s\u22121 C. 5 3rad.s\u22121 D. 2,5rad.s\u22121 Con l\u1eafc l\u00f2 xo c\u00f3 v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 400g \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. H\u00ecnh b\u00ean l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a \u0111\u1ed9ng n\u0103ng W\u0111 c\u1ee7a con l\u1eafc theo th\u1eddi gian t. T\u1ea1i t = 0, v\u1eadt \u0111ang chuy\u1ec3n \u0111\u1ed9ng theo chi\u1ec1u d\u01b0\u01a1ng. L\u1ea5y \u03c02 = 10. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. x = 5cos\uf0e6\uf0e7\uf0e8 2\uf070t + \uf070 \uf0f6\uf0f7\uf0f8(cm) B. x = 10 cos \uf0e6 \uf070t + \uf070 \uf0f6\uf0f7\uf0f8(cm ) 3 \uf0e7\uf0e8 6 C. x = 5cos\uf0e6\uf0e7\uf0e8 2\uf070t \u2212 \uf070 \uf0f6 ( cm) D. x = 10 cos \uf0e6 \uf070t \u2212 \uf070 \uf0f6 ( cm) 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 \u0111\u1ed3 th\u1ecb th\u1ebf n\u0103ng nh\u01b0 h\u00ecnh v\u1ebd. T\u1ea1i t = 0, v\u1eadt c\u00f3 gia t\u1ed1c \u00e2m. L\u1ea5y \u03c02 = 10. Ph\u01b0\u01a1ng tr\u00ecnh v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt l\u00e0 A. v = 60\uf070 cos \uf0e6 5\uf070t + \uf070 \uf0f6\uf0f7\uf0f8(cm \/ s) \uf0e7\uf0e8 4 B. v = 60\uf070 cos \uf0e6 5\uf070t + 3\uf070 \uf0f6\uf0f7\uf0f8(cm \/ s) \uf0e7\uf0e8 4 C. v = 60\uf070sin \uf0e6\uf0e7\uf0e810\uf070t \u2212 3\uf070 \uf0f6\uf0f7\uf0f8(cm \/ s) 4 D. v = 60\uf070cos\uf0e6\uf0e7\uf0e810\uf070t + \uf070 \uf0f6 ( cm \/ s) 4 \uf0f7\uf0f8 TRANG 69","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A \u2013 CH\u1ee6 \u0110\u1ec0 2 1.D 2.D B\u1ea2NG \u0110\u00c1P \u00c1N 9.D 10.C 11.C 12.C 19.C 20.A 21.D 22.B 3.C 4.B 5.D 6.C 7.C 8.C 29.D 30.D 31.B 32.D 13.C 14.C 15.A 16.C 17.C 18.D 39.A 40.A 41.A 42.A 23.D 24.C 25.C 26.B 27.C 28.D 49.B 50.A 51.A 52.A 33.B 34.C 35.C 36.B 37.A 38.A 59.D 60.B 61.B 62.C 43.D 44.A 45.B 46.C 47.C 48.D 69.A 70.D 71.D 72.A 53.A 54.A 55.A 56.A 57.C 58.C 79.B 80.C 81.C 82.A 63.B 64.A 65.B 66.A 67.A 68.A 89.C 90.D 91.C 92.A 73.D 74.B 75.A 76.D 77.A 78.D 99.A 100.C 101.B 102.A 83.D 84.C 85.C 86.D 87.A 88.B 109.B 110.D 111.B 112.B 93.C 94.C 95.D 96.A 97.A 98.A 119.C 120.A 121.A 122.A 103.C 104.C 105.B 106.A 107.C 108.B 129.A 130.A 131.D 132.D 113.A 114.A 115.C 116.B 117.C 118.C 139.A 140.C 141.A 142.A 123.D 124.A 125.A 126.C 127.D 128.C 149.B 150.D 151.D 152.A 133.D 134.C 135.A 136.A 137.A 138.A 143.A 144.D 145.C 146.D 147.D 148.B 9.C 1.D 2.D 153.D 154.C 155.D 156.A B\u1ea2NG \u0110\u00c1P \u00c1N \u2013 Ph\u1ea7n \u0111\u1ed3 th\u1ecb 3.D 4.A,D 5.D 6.D 7.B 8.C QR CODE PDF L\u1eddi gi\u1ea3i TRANG 70","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 CH\u1ee6 \u0110\u1ec0 3: CON L\u1eaeC \u0110\u01a0N CH\u1ee6 \u0110\u1ec0 3: CON L\u1eaeC \u0110\u01a0N D\u1ea0NG 1: PH\u01af\u01a0NG TR\u00ccNH DAO \u0110\u1ed8NG C\u1ee6A CON L\u1eaeC \u0110\u01a0N PH\u01af\u01a0NG TR\u00ccNH DAO \u0110\u1ed8NG C\u00c1C \u0110\u1ea0I L\u01af\u1ee2NG \u0110\u1eb6C TR\u01afNG \u2756 T\u1ea7n s\u1ed1 g\u1ed1c, t\u1ea7n s\u1ed1, chu k\u00ec: w= g; f= 1 g ; T = 2\uf070 2\uf070 g \u2756 Bi\u00ean \u0111\u1ed9 d\u00e0i ( bi\u00ean \u0111\u1ed9 cong): So = \uf061o. = s2 + v2 ; s = \uf061. w2 \u2756 Bi\u00ean \u0111\u1ed9 g\u00f3c: \uf061o2 = \uf0612 + v2 g ( )\u2756 Theo li \u0111\u1ed9 d\u00e0i: s = so.cos wt + \uf06a (cm; m) \u2756 Ch\u00fa \u00fd: C\u00e1c c\u00f4ng th\u1ee9c \u03b1 ho\u1eb7c \u03b1o \u0111\u1ee9ng \u201cc\u00f4 \u0111\u01a1n\u201d 1 m\u00ecnh c\u00e1c em ph\u1ea3i \u0111\u1ed5i sang \u0111\u01a1n v\u1ecb rad \u0111\u1ec3 t\u00ednh. ( )\u2756 Theo li \u0111\u1ed9 g\u00f3c: \uf061 = \uf061o.cos wt + \uf06a (rad) C\u00e2u 1: (Minh H\u1ecda -2021) T\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g, m\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi t\u1ea7n s\u1ed1 g\u00f3c l\u00e0 A. \uf077 = B. \uf077 = 2\uf070 g C. \uf077 = g D. \uf077 = 2\uf070 g g C\u00e2u 2: (\u0110H-2021) M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng tr\u00ecnh s = so.cos(wt + \uf06a) (so \uf03e 0) . C\u00e2u 3: \u0110\u1ea1i l\u01b0\u1ee3ng So \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0: B. Pha ban \u0111\u1ea7u c\u1ee7a dao \u0111\u1ed9ng C\u00e2u 4: A. Li \u0111\u1ed9 g\u00f3c c\u1ee7a dao \u0111\u1ed9ng C\u00e2u 5: C\u00e2u 6: B. T\u1ea7n s\u1ed1 c\u1ee7a dao \u0111\u1ed9ng D. bi\u00ean \u0111\u1ed9 c\u1ee7a dao \u0111\u1ed9ng (\u0110H-2018) M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh s=3cos(\u03c0t + 0,5\u03c0) (cm) (t t\u00ednh b\u1eb1ng gi\u00e2y). T\u1ea7n s\u1ed1 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc n\u00e0y l\u00e0: A. 2 Hz B. 4\u03c0 Hz C. 0,5 Hz D. 0,5\u03c0 Hz (\u0110H-2019) T\u1ea1i m\u1ed9t n\u01a1i tr\u00ean m\u1eb7t \u0111\u1ea5t c\u00f3 g=9,87 m\/s2, m\u1ed9t con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec 2s. Chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc l\u00e0: A. 40cm B. 25cm C. 100cm D. 50cm (Minh H\u1ecda-2020) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 g=9,8 m\/s2. Chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. 2s B. 1s C. 0,5s D. 9,8s (\u0110H-2020) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 81 cm \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 80 t\u1ea1i n\u01a1i c\u00f3 g = 9,87 m\/s2 (\u03c02 = 9,87). Ch\u1ecdn t = 0 khi v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt nh\u1ecf \u0111i \u0111\u01b0\u1ee3c trong kho\u1ea3ng th\u1eddi gian t\u1eeb t= 0 \u0111\u1ebfn t =1,2s l\u00e0 A. 26,5 cm B. 30,2 cm C. 32,4 cm D. 28,3cm TRANG 71","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 7: Con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i =1m, g=10m\/s2. K\u00edch th\u00edch cho con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. T\u00ednh chu k\u00ec c\u1ee7a con l\u1eafc, l\u1ea5y \u03c02=10 A. 0,5s B. 1s C. 4s D. 2s C\u00e2u 8: Con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 chu k\u00ec T=2s, bi\u1ebft g=\u03c02=10. T\u00ednh chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc \u0111\u01a1n: A. 0,4m B. 1m C. 0,04m D. 2m C\u00e2u 9: Con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 d\u00e0i So=5cm, bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1o=0,1 rad\/s. T\u00ecm chu k\u00ec c\u1ee7a con l\u1eafc \u0111\u01a1n n\u00e0y, bi\u1ebft g=10=\u03c02 A. 2s B. 1s C. 1 s D. 2 s 2 C\u00e2u 10: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng nh\u1ecf \u1edf n\u01a1i c\u00f3 g=10m\/s2 v\u1edbi chu k\u00ec T=2s tr\u00ean qu\u1ef9 \u0111\u1ea1o d\u00e0i 24cm. T\u1ea7n s\u1ed1 g\u00f3c v\u00e0 bi\u00ean \u0111\u1ed9 g\u00f3c c\u00f3 gi\u00e1 tr\u1ecb b\u1eb1ng: A. w=2\u03c0 rad\/s; \u03b1o=0,24 rad B. w=\u03c0 rad\/s; \u03b1o=0,24 rad C. w=2\u03c0 rad\/s; \u03b1o=0,12 rad D. w=\u03c0 rad\/s; \u03b1o=0,12 rad C\u00e2u 11: T\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 9,8 m\/s2, m\u1ed9t con l\u1eafc \u0111\u01a1n v\u00e0 m\u1ed9t con l\u1eafc l\u00f2 xo n\u1eb1m ngang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi c\u00f9ng t\u1ea7n s\u1ed1. Bi\u1ebft con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 49cm v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 10N\/m. Kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc l\u00f2 xo l\u00e0: A. 0,125 kg B. 0,750 kg C. 0,500 kg D. 0,250 kg C\u00e2u 12: M\u1ed9t con l\u1eafc \u0111\u01a1n s\u1ee3i c\u00f3 d\u00e2y treo kh\u00f4ng d\u00e3n c\u00f3 tr\u1ecdng l\u01b0\u1ee3ng kh\u00f4ng \u0111\u00e1ng k\u1ec3, chi\u1ec1u d\u00e0i 10 cm \u0111\u01b0\u1ee3c treo th\u1eb3ng \u0111\u1ee9ng \u1edf \u0111i\u1ec3m A. Truy\u1ec1n cho qu\u1ea3 c\u1ea7u \u0111\u1ed9ng n\u0103ng theo ph\u01b0\u01a1ng ngang \u0111\u1ec3 n\u00f3 \u0111\u1ebfn v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 g\u00f3c 0,075 (rad) th\u00ec c\u00f3 t\u1ed1c \u0111\u1ed9 0,075 3 (m\/s). Bi\u1ebft con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng h\u00ecnh \u1ee9ng v\u1edbi li \u0111\u1ed9 d\u00e0i s = Asin(\u03c9t + \u03c6). Cho gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10 (m\/s2). Ch\u1ecdn g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac qu\u1ea3 c\u1ea7u c\u00f3 li \u0111\u1ed9 g\u00f3c 0,075 (rad) theo chi\u1ec1u d\u01b0\u01a1ng. T\u00ednh \u03c6. \uf070 5\uf070 C. \u2212 \uf070 D. \u2212 5\uf070 A. B. . 6 6 6 6 C\u00e2u 13: Con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 2m. K\u00e9o con l\u1eafc v\u1ec1 ph\u00eda ph\u1ea3i m\u1ed9t g\u00f3c 0,15 rad so v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng r\u1ed3i bu\u00f4ng nh\u1eb9, l\u1ea5y g=9,8 m\/s2. Ch\u1ecdn g\u1ed1c t\u1ecda \u0111\u1ed9 t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, chi\u1ec1u d\u01b0\u01a1ng h\u01b0\u1edbng t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng sang ph\u00eda ph\u1ea3i, g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u1ea7n th\u1ee9 hai. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. s = 30sin (2\uf070t) (cm) B. s = 30sin (2,2t ) (cm) C. s = 30cos(2,2t + \uf070) (cm) D. s = 30cos(2\uf070t + \uf070) (cm) C\u00e2u 14: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee9 sao 1\/8 (s) th\u00ec \u0111\u1ed9ng n\u0103ng l\u1ea1i b\u1eb1ng th\u1ebf n\u0103ng. Qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt \u0111i \u0111\u01b0\u1ee3c trong 0,5s l\u00e0 16cm. Ch\u1ecdn g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng theo chi\u1ec1u \u00e2m. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. s = 8cos \uf0e6 2\uf070t + \uf070\uf0f6 (cm) B. s = 4cos \uf0e6 4\uf070t + \uf070\uf0f6 (cm) \uf0e7\uf0e8 2 \uf0f7\uf0f8 \uf0e7\uf0e8 2 \uf0f7\uf0f8 C. s = 8cos \uf0e6 2\uf070t \u2013 \uf070\uf0f6 (cm) D. s = 4cos \uf0e6 4\uf070t \u2013 \uf070\uf0f6 (cm) \uf0e7\uf0e8 2 \uf0f8\uf0f7 \uf0e7\uf0e8 2 \uf0f7\uf0f8 TRANG 72","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 15: Con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 = \uf0702 m\/s2 v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh \uf061 = 0, 04 cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 rad, t \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng gi\u00e2y. K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u \u0111\u1ebfn khi v\u1eadt \u0111i qua v\u1ecb \uf0e7\uf0e8 3 \uf0f7\uf0f8 tr\u00ed c\u00e2n b\u1eb1ng l\u1ea7n th\u1ee9 hai th\u00ec qu\u00e3ng \u0111\u01b0\u1eddng m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c l\u00e0 A. 2 cm. B. 1,5 cm. C. 3,5 cm. D. 4 cm. C\u00e2u 16: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng nh\u1ecf xung quanh v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, ch\u1ecdn tr\u1ee5c Ox n\u1eb1m ngang g\u1ed1c O tr\u00f9ng v\u1edbi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng chi\u1ec1u d\u01b0\u01a1ng h\u01b0\u1edbng t\u1eeb tr\u00e1i sang ph\u1ea3i. \u1ede th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt \u1edf b\u00ean tr\u00e1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 0,01 rad, v\u1eadt \u0111\u01b0\u1ee3c truy\u1ec1n t\u1ed1c \u0111\u1ed9 \u03c0 cm\/s v\u1edbi chi\u1ec1u t\u1eeb ph\u1ea3i sang tr\u00e1i.Bi\u1ebft n\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 0,1 (mJ), kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt l\u00e0 100g, l\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10m\/s2 v\u00e0 \u03c02=10. Vi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt A. s = 2.cos \uf0e6 \uf070t + 3\uf070 \uf0f6 (cm) B. s = 4.cos \uf0e6 2\uf070t + 3\uf070 \uf0f6 (cm) \uf0e7\uf0e8 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 C. s = 2.cos \uf0e6 \uf070t \u2212 \uf070\uf0f6 (cm) D. s = 4.cos \uf0e6 2\uf070t \u2212 \uf070\uf0f6 (cm) \uf0e7\uf0e8 4 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 C\u00e2u 17: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l=1m, \u0111\u01b0\u1ee3c g\u1eafn v\u1eadt m=0,1kg. K\u00e9o v\u1eadt ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t g\u00f3c \u03b1=100 r\u1ed3i bu\u00f4ng tay kh\u00f4ng v\u1eadn t\u1ed1c ban \u0111\u1ea7u cho v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c trong tr\u01b0\u1eddng g=\u03c02=10 m\/s2. Ch\u1ecdn th\u1eddi g\u1ed1c th\u1eddi gian t=0 l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng theo chi\u1ec1u d\u01b0\u01a1ng. Vi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt: A. \uf061 = 10.cos \uf0e6 \uf070t \u2013 \uf070\uf0f6 rad C. \uf061 = \uf070 .cos \uf0e6 \uf070t \u2013 \uf070\uf0f6 rad \uf0e7\uf0e8 2 \uf0f8\uf0f7 18 \uf0e7\uf0e8 2 \uf0f7\uf0f8 C. \uf061 = \uf070 .cos \uf0e6 2\uf070t \u2013 \uf070 \uf0f6 rad D. \uf061 = 1 .cos \uf0e6 \uf070t \u2013 \uf070\uf0f6 rad 18 \uf0e7\uf0e8 2 \uf0f7\uf0f8 10 \uf0e7\uf0e8 2 \uf0f7\uf0f8 C\u00e2u 18: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 20cm \u0111ang dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 60 t\u1ea1i n\u01a1i c\u00f3 gi\u00e1 t\u1ed1c g=9,8 m\/s2. T\u1ea1i th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 g\u00f3c 30 theo chi\u1ec1u d\u01b0\u01a1ng. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. s = 2\uf070 .cos \uf0e6 7t \u2212 \uf070 \uf0f6 (cm) B. s= 2\uf070 .cos \uf0e6 7t + \uf070 \uf0f6 (cm) 3 \uf0e7\uf0e8 3 \uf0f7\uf0f8 3 \uf0e7\uf0e8 3 \uf0f7\uf0f8 C. s= 2\uf070 .cos \uf0e6 7t + 2\uf070 \uf0f6 (cm) D. s = \uf070 .cos \uf0e6\uf0e7\uf0e8 7t \u2212 \uf070\uf0f6 (cm) 30 \uf0e7\uf0e8 3 \uf0f7\uf0f8 30 3 \uf0f7\uf0f8 C\u00e2u 19: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i = 1m \u0111\u01b0\u1ee3c k\u00edch th\u00edch dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 = \uf0702 m\/s2. Ban \u0111\u1ea7u \u0111\u01b0a v\u1eadt \u0111\u1ebfn v\u1ecb tr\u00ed d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 = 0,04 rad r\u1ed3i truy\u1ec1n cho n\u00f3 v\u1eadn t\u1ed1c ban \u0111\u1ea7u v0 = 4 30 cm\/s theo ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi d\u00e2y treo h\u01b0\u1edbng ra x v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, qu\u00e3ng \u0111\u01b0\u1eddng m\u00e0 v\u1eadt \u0111i \u0111\u01b0\u1ee3c cho \u0111\u1ebfn khi n\u00f3 \u0111\u1ed5i chi\u1ec1u l\u1ea7n th\u1ee9 hai l\u00e0 A. 20 cm. B. 10 cm. C. 15 cm. D. 25 cm. C\u00e2u 20: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m s\u1ee3i d\u00e2y c\u00f3 chi\u1ec1u d\u00e0i 20cm treo t\u1ea1i m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh. K\u00e9o con l\u1eafc kh\u1ecfi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c b\u1eb1ng 0,1 rad v\u1ec1 ph\u00eda b\u00ean ph\u1ea3i r\u1ed3i truy\u1ec1n cho n\u00f3 t\u1ed1c \u0111\u1ed9 b\u1eb1ng 14 3 cm\/s theo ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi d\u00e2y. Cho gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g= 9,8 m\/s2. T\u00ednh bi\u00ean \u0111\u1ed9 d\u00e0i: A. 3,2 cm B. 2,8 cm C. 4 cm D. 6 cm TRANG 73","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 21: T\u1ea1i n\u01a1i c\u00f3 g=9,8 m\/s2, m\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i d\u00e2y treo 1m, \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 0,1 rad. \u1ede v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 g\u00f3c 0,05 rad, v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc con t\u1ed1c \u0111\u1ed9 l\u00e0: A. 2,7 cm\/s B. 27,1 cm\/s C. 1,6 cm\/s D. 15,7 cm\/s C\u00e2u 22: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 0,1 rad \u1edf m\u1ed9t n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g= 10m\/s2. V\u00e0o th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u v\u1eadt \u0111i qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 d\u00e0i 8cm v\u00e0 v\u1eadn t\u1ed1c 20 3 cm\/s. T\u1ed1c \u0111\u1ed9 c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt dao \u0111\u1ed9ng l\u00e0: A. 0,8 m\/s B. 0,2 m\/s C. 0,4 m\/s D. 1 m\/s C\u00e2u 23: M\u1ed9t con l\u1eafc \u0111\u01a1n d\u00e2y treo c\u00f3 chi\u1ec1u d\u00e0i 25cm. V\u1eadt nh\u1ecf con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 0,08 rad t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2, l\u1ea5y \u03c02=10. Kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 v\u1eadt \u0111i \u0111\u01b0\u1ee3c qu\u00e3ng \u0111\u01b0\u1eddng 6cm l\u00e0: A. 2\/3s B. 3\/4s C. 0,5s D. 0,4s C\u00e2u 24: (Chuy\u00ean Phan B\u1ed9i Ch\u00e2u \u2013 2017) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 40 cm, \u0111\u01b0\u1ee3c treo t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng b\u1eb1ng 10 m\/s2. B\u1ecf qua l\u1ef1c c\u1ea3n c\u1ee7a kh\u00f4ng kh\u00ed. \u0110\u01b0a d\u00e2y treo l\u1ec7ch kh\u1ecfi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 0,15 rad r\u1ed3i th\u1ea3 nh\u1eb9. T\u1ed1c \u0111\u1ed9 c\u1ee7a qu\u1ea3 n\u1eb7ng t\u1ea1i v\u1ecb tr\u00ed d\u00e2y treo l\u1ec7ch kh\u1ecfi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 0,12 rad b\u1eb1ng A. 6 cm\/s. B. 24 cm\/s. C. 18 cm\/s. D. 30 cm\/s. C\u00e2u 25: Con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 = \uf0702 m\/s2 v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh \uf061 = 0, 04 cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 rad, t \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng gi\u00e2y. K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u \u0111\u1ebfn khi v\u1eadt \u0111i qua v\u1ecb \uf0e7\uf0e8 3 \uf0f7\uf0f8 tr\u00ed bi\u00ean d\u01b0\u01a1ng l\u1ea7n th\u1ee9 2021 th\u00ec t\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a v\u1eadt l\u00e0: A. 4,0 cm\/s. B. 3,3 cm\/s. C. 2,6 cm\/s. D. 1,5 cm\/s. C\u00e2u 26: T\u1ea1i m\u1ed9t n\u01a1i tr\u00ean Tr\u00e1i \u0110\u1ea5t, c\u00f3 hai con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b101 v\u00e0 \u03b102; chu k\u00ec t\u01b0\u01a1ng \u1ee9ng l\u00e0 T1 v\u00e0 T2 v\u00e0 T2 = 2 T\u1ea1i t=0, c\u1ea3 hai con l\u1eafc \u0111\u1ec1u \u1edf v\u1ecb tr\u00ed bi\u00ean. Sau kho\u1ea3ng gian 5 T1 . T1 k\u1ec3 t\u1eeb t=0, qu\u00e3ng \u0111\u01b0\u1eddng m\u00e0 v\u1eadt nh\u1ecf c\u1ee7a hai con l\u1eafc \u0111i \u0111\u01b0\u1ee3c b\u1eb1ng nhau. T\u1ec9 s\u1ed1 \uf06101 b\u1eb1ng: 3 \uf06102 15 28 75 14 A. B. C. D. 14 75 28 15 TRANG 74","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 2: B\u00c0I TO\u00c1N THAY \u0110\u1ed4I CHI\u1ec0U D\u00c0I C\u1ee6A CON L\u1eaeC \u0110\u01a0N CHU K\u1ef2 C\u1ee6A CON L\u1eaeC \u0110\u01a0N PH\u01af\u01a0NG PH\u00c1P T\u1ec8 L\u1ec6 \u2756Ch\u00fa \u00fd: Chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a \u2756 Ta c\u00f3: T ~ \uf0f0 ~ T2 con l\u1eafc \u0111\u01a1n kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a v\u1eadt n\u1eb7ng. \u2756 Khi CL\u0110 c\u00f3 chi\u1ec1u d\u00e0i 1 th\u00ec n\u00f3 dao \u0111\u1ed9ng v\u1edbi T1 \u2756 Khi CL\u0110 c\u00f3 chi\u1ec1u d\u00e0i 2 th\u00ec n\u00f3 dao \u0111\u1ed9ng v\u1edbi T2 T = 2\uf070 = \uf044t \u2756 Khi CL\u0110 c\u00f3 chi\u1ec1u d\u00e0i: 3 = a. 1 + b. 2 gN T32 = a.T12 + b.T22 \u2756 N\u1ebfu x\u00e9t t\u1ea1i m\u1ed9t n\u01a1i tr\u00ean Tr\u00e1i \u0110\u1ea5t, ta c\u00f3: T1 = 1 = N2 T2 2 N1 C\u00e2u 27: (S\u1edf H\u00e0 N\u1ed9i-2020) Chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc \u0111\u01a1n kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o A. V\u0129 \u0111\u1ed9 \u0111\u1ecba l\u00fd B. Gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng C. Chi\u1ec1u d\u00e0i d\u00e2y treo D. Kh\u1ed1i l\u01b0\u1ee3ng qu\u1ea3 n\u1eb7ng C\u00e2u 28: (\u0110H-2019) T\u1ea1i m\u1ed9t n\u01a1i tr\u00ean m\u1eb7t \u0111\u1ea5t, m\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec 2s. N\u1ebfu chi\u1ec1u d\u00e0i con l\u1eafc gi\u1ea3m \u0111i 4 l\u1ea7n th\u00ec chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00fac n\u00e0y l\u00e0: A. 4s B. 8s C. 0,5s D. 1s C\u00e2u 29: T\u1ea1i m\u1ed9t n\u01a1i, chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a m\u1ed9t con l\u1eafc \u0111\u01a1n l\u00e0 2,2s. Sau khi gi\u1ea3m chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc 21cm th\u00ec chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a n\u00f3 l\u00e0 2,0s. Chi\u1ec1u d\u00e0i ban \u0111\u1ea7u c\u1ee7a con l\u1eafc l\u00e0: A. 100cm B. 99cm C. 98cm D. 121cm C\u00e2u 30: T\u1ea1i m\u1ed9t n\u01a1i con l\u1eafc \u0111\u01a1n c\u00f3 \u0111\u1ed9 d\u00e0i 1 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T1=5(s), con l\u1eafc \u0111\u01a1n c\u00f3 \u0111\u1ed9 d\u00e0i 2 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T2=4(s). T\u1ea1i \u0111\u00f3, CL\u0110 c\u00f3 \u0111\u1ed9 d\u00e0i = 1 - 2 s\u1ebd dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec: A. T=1s B. T=5s C. T=3s D. T=7\/12s C\u00e2u 31: M\u1ed9t con l\u1eafc \u0111\u01a1n, trong kho\u1ea3ng th\u1eddi gian \u0394t n\u00f3 th\u1ef1c hi\u1ec7n 12 dao \u0111\u1ed9ng. Khi gi\u1ea3m \u0111\u1ed9 d\u00e0i c\u1ee7a n\u00f3 b\u1edbt 16cm, trong c\u00f9ng kho\u1ea3ng th\u1eddi gian \u0394t nh\u01b0 tr\u00ean, con l\u1eafc th\u1ef1c hi\u1ec7n 20 dao \u0111\u1ed9ng. T\u00ednh \u0111\u1ed9 d\u00e0i ban \u0111\u1ea7u. A. 60 cm. B. 50 cm. C. 40 cm. D. 25 cm. C\u00e2u 32: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i , trong kho\u1ea3ng th\u1eddi gian \u0394t n\u00f3 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 12 dao \u0111\u1ed9ng. Khi gi\u1ea3m chi\u1ec1u d\u00e0i \u0111i 32cm c\u0169ng trong kho\u1ea3ng th\u1eddi gian \u0394t n\u00f3i tr\u00ean, con l\u1eafc th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 20 dao \u0111\u1ed9ng. Chi\u1ec1u d\u00e0i ban \u0111\u1ea7u c\u1ee7a con l\u1eafc l\u00e0: A. 30cm B. 40cm C. 50cm D. 60cm C\u00e2u 33: C\u00f3 hai con l\u1eafc \u0111\u01a1n m\u00e0 \u0111\u1ed9 d\u00e0i c\u1ee7a ch\u00fang kh\u00e1c nhau 22cm, dao \u0111\u1ed9ng \u1edf c\u00f9ng m\u1ed9t n\u01a1i. Trong c\u00f9ng m\u1ed9t kho\u1ea3ng th\u1eddi gian, con l\u1eafc th\u1ee9 nh\u1ea5t th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 30 dao \u0111\u1ed9ng, con l\u1eafc th\u1ee9 2 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 36 dao \u0111\u1ed9ng. \u0110\u1ed9 d\u00e0i c\u1ee7a c\u00e1c con l\u1eafc l\u00e0: A. 1=88cm, 2=110cm B. 1=72cm, 2=50cm C. 1= 78cm, 2=110cm D. 1=50cm, 2=72cm C\u00e2u 34: Hai con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l\u1ea7n l\u01b0\u1ee3t l\u00e0 1 v\u00e0 2, \u0111\u01b0\u1ee3c treo \u1edf tr\u1ea7n m\u1ed9t c\u0103n ph\u00f2ng, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec t\u01b0\u01a1ng \u1ee9ng l\u00e0 2,0s v\u00e0 1,8s. T\u1ec9 s\u1ed1 2 \/ 1 b\u1eb1ng: A. 0,81 B. 1,11 C. 1,23 D. 0,90 D. T\u0103ng 0,1% C\u00e2u 35: Chi\u1ec1u d\u00e0i c\u1ee7a CL\u0110 t\u0103ng 1% th\u00ec chu k\u00ec dao \u0111\u1ed9ng s\u1ebd: A. T\u0103ng 1% B. T\u0103ng 0,5% C. Gi\u1ea3m 0,5% TRANG 75","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 36: \u0110\u1ec3 chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc \u0111\u01a1n t\u0103ng th\u00eam 5% th\u00ec ph\u1ea3i t\u0103ng chi\u1ec1u d\u00e0i: A. 5,75% B. 2,25% C. 10,25% D. 25% C\u00e2u 37: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m qu\u1ea3 n\u1eb7ng nh\u1ecf v\u00e0 d\u00e2y treo c\u00f3 chi\u1ec1u c\u00f3 th\u1ec3 thay \u0111\u1ed5i \u0111\u01b0\u1ee3c. N\u1ebfu chi\u1ec1u d\u00e0i d\u00e2y treo l\u00e0 1 th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 1s. N\u1ebfu chi\u1ec1u d\u00e0i d\u00e2y treo l\u00e0 2 th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 2s. N\u1ebfu chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc l\u00e0 3=4 1+ 3 2 th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc A. 3s B. 4s C. 5s D. 6s C\u00e2u 38: Hai con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i d\u00e2y treo v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt n\u1eb7ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 1 , m1 v\u00e0 2 , m2 . Bi\u1ebft con l\u1eafc 1 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T1 = 3 s, con l\u1eafc 2 dao \u0111\u1ed9ng v\u1edbi chu k\u00ec T2 = 4 s. Con l\u1eafc c\u00f3 chi\u1ec1u d\u00e0i = 1 + 2 v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng m = m1 + m2 s\u1ebd dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec A. 1 s. B. 5 s. C. 3 s. D. 4 s. C\u00e2u 39: (\u0110H-2017)Ti\u1ebfn h\u00e0nh th\u00ed nghi\u1ec7m \u0111o gia t\u1ed1c trong tr\u01b0\u1eddng b\u1eb1ng con l\u1eafc \u0111\u01a1n, m\u1ed9t h\u1ecdc sinh \u0111o \u0111\u01b0\u1ee3c chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc l\u00e0 119 \uf0b1 1 (cm), chu k\u00ec dao \u0111\u1ed9ng nh\u1ecf c\u1ee7a n\u00f3 l\u00e0 2,20 \uf0b1 0,01 (s). L\u1ea5y \u03c02=9,87 v\u00e0 b\u1ecf qua sai s\u1ed1 c\u1ee7a s\u1ed1 \u03c0. Gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng \u0111o \u0111\u01b0\u1ee3c t\u1ea1i n\u01a1i l\u00e0m th\u00ed nghi\u1ec7m l\u00e0: A. g=9,7 \uf0b1 0,1(m\/s2) B. g=9,8 \uf0b1 0,2(m\/s2) C. g=9,8 \uf0b1 0,1(m\/s2) D. g=9,7 \uf0b1 0,2(m\/s2) C\u00e2u 40: (\u0110H-2017) Ti\u1ebfn h\u00e0nh th\u00ed nghi\u1ec7m \u0111o gia t\u1ed1c trong tr\u01b0\u1eddng b\u1eb1ng con l\u1eafc \u0111\u01a1n, m\u1ed9t h\u1ecdc sinh \u0111o \u0111\u01b0\u1ee3c chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc l\u00e0 99 \uf0b1 1 (cm), chu k\u00ec dao \u0111\u1ed9ng nh\u1ecf c\u1ee7a n\u00f3 l\u00e0 2,00 \uf0b1 0,02 (s). L\u1ea5y \u03c02=9,87 v\u00e0 b\u1ecf qua sai s\u1ed1 c\u1ee7a s\u1ed1 \u03c0. Gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng do h\u1ecdc sinh \u0111o \u0111\u01b0\u1ee3c t\u1ea1i n\u01a1i l\u00e0m th\u00ed nghi\u1ec7m l\u00e0: A. g=9,7 \uf0b1 0,2(m\/s2) B. g=9,8 \uf0b1 0,3(m\/s2) C. g=9,8 \uf0b1 0,2(m\/s2) D. g=9,7 \uf0b1 0,3(m\/s2) C\u00e2u 41: (Minh H\u1ecda \u2013 2021)Trong b\u00e0i th\u1ef1c h\u00e0nh \u0111o gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g b\u1eb1ng con l\u1eafc \u0111\u01a1n, m\u1ed9t nh\u00f3m h\u1ecdc sinh ti\u1ebfn h\u00e0nh \u0111o, x\u1eed l\u00fd s\u1ed1 li\u1ec7u v\u00e0 v\u1ebd \u0111\u01b0\u1ee3c \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a b\u00ecnh ph\u01b0\u01a1ng chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a (T 2 ) theo chi\u1ec1u d\u00e0i c\u1ee7a con l\u1eafc nh\u01b0 h\u00ecnh b\u00ean. L\u1ea5y \u03c0 = 3,14. Gi\u00e1 tr\u1ecb trung b\u00ecnh c\u1ee7a g \u0111o \u0111\u01b0\u1ee3c trong th\u00ed nghi\u1ec7m n\u00e0y l\u00e0 A. 9,96 m\/s 2 B. 9,42 m\/s 2 C. 9,58 m\/s 2 D. 9,74 m\/s 2 C\u00e2u 42: (VDC \u2013 \u0110H2021) \u1ede m\u1ed9t n\u01a1i tr\u00ean m\u1eb7t \u0111\u1ea5t, hai con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i v\u00e0 4 \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a trong c\u00f9ng m\u1ed9t m\u1eb7t ph\u1eb3ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi c\u00f9ng bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1o=9,00. Quan s\u00e1t c\u00e1c con l\u1eafc dao \u0111\u1ed9ng th\u00ec th\u1ea5y: khi c\u00e1c d\u00e2y treo c\u1ee7a hai con l\u1eafc song song v\u1edbi nhau th\u00ec li \u0111\u1ed9 g\u00f3c c\u1ee7a m\u1ed9t con l\u1eafc ch\u1ec9 c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb \u03b11 ho\u1eb7c gi\u00e1 tr\u1ecb \u03b12 ( \u03b11 \u2260 \u03b12 ). T\u1ed5ng \uf0611 + \uf0612 c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y A. 7,50 B. 11,50 C. 13,80 D. 8,80 TRANG 76","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 3: N\u0102NG L\u01af\u1ee2NG C\u1ee6A CON L\u1eaeC \u0110\u01a0N \u0110\u1ed8NG N\u0102NG C\u01a0 N\u0102NG \u2756 W\u0111 = 1 mv2 = W \u2212 Wt = m.g. .(cos \uf061 \u2212 cos \uf061o ) \u2756 W = W\u00f1 + Wt = m.g. .(1 \u2212 cos\uf0610) 2 1 m.g. 1 \u2756 1 .(\uf061o2 \u2212 \uf0612) \u2756 W= 2 .\uf06102 = 2 m.w 2 .s 2 2 W\u0111 = m.g. o TH\u1ebe N\u0102NG L\u1ef0C K\u00c9O V\u1ec0 \u2756 \u0110\u1ed9 l\u1edbn: F = m. g .s = m.g.\uf061 \u2756 Wt = m.g. .(1\u2212 cos\uf061) = 1 m.g. .\uf0612 2 \u2756 \u0110\u1ed9 l\u1edbn c\u1ef1c \u0111\u1ea1i: F = m. g .So = m.g.\uf061o M\u1ed0I QUAN H\u1ec6 GI\u1eeeA \u2756 Khi W\u0111 =nWt \uf0de \uf061 = \uf0b1 \uf061o \u0110\u1ed8NG N\u0102NG & TH\u1ebe N\u0102NG n +1 \u2756 Kho\u1ea3ng th\u1eddi gian gi\u1eefa hai l\u1ea7n li\u00ean ti\u1ebfp W\u0111=Wt l\u00e0 T 4 C\u00e2u 43: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m kh\u1ed1i l\u01b0\u1ee3ng 100g dao \u0111\u1ed9ng trong m\u1eb7t ph\u1eb3ng th\u1eb1ng \u0111\u1ee9ng \u0111i qua \u0111i\u1ec3m treo t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2. L\u1ea5y m\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. B\u1ecf qua ma s\u00e1t. Khi s\u1ee3i d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 300 th\u00ec t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt n\u1eb7ng l\u00e0 0,3m\/s. C\u01a1 n\u0103ng c\u1ee7a con l\u1eafc \u0111\u01a1n l\u00e0: A. 0,1J B. 0,13J C. 0,14J D. 0,5J C\u00e2u 44: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=200g, =80cm treo t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2. Khi dao \u0111\u1ed9ng n\u00f3 v\u1ea1ch ra m\u1ed9t cung tr\u00f2n c\u00f3 th\u1ec3 coi nh\u01b0 m\u1ed9t \u0111o\u1ea1n th\u1eb3ng d\u00e0i 4cm. N\u0103ng l\u01b0\u1ee3ng c\u1ee7a con l\u1eafc khi dao \u0111\u1ed9ng: A. 8.10-4J B. 0,008 J C. 0,04 J D. 5.10-4J C\u00e2u 45: M\u1ed9t con l\u1eafc \u0111\u01a1n m\u00e0 v\u1eadt dao \u0111\u1ed9ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 0,2kg v\u00e0 \u0111\u1ed9 d\u00e0i d\u00e2y treo l\u00e0 0,5m, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=10m\/s2.V\u1eadt dao \u0111\u1ed9ng v\u1ea1ch ra m\u1ed9t cung tr\u00f2n c\u00f3 th\u1ec3 coi nh\u01b0 m\u1ed9t \u0111o\u1ea1n th\u1eb3ng d\u00e0i 4cm. T\u00ednh c\u01a1 n\u0103ng c\u1ee7a con l\u1eafc: A. 80 \u03bcJ B. 8mJ C. 0,04J D. 0,8mJ C\u00e2u 46: Con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i =98cm, kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt n\u1eb7ng l\u00e0 m=90g dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b10=60 t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=9,8m\/s2. C\u01a1 n\u0103ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00e0: A. 0,09J B. 1,58J C. 1,62J D. 0,0047J C\u00e2u 47: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m qu\u1ea3 c\u1ea7u c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 400g v\u00e0 s\u1ee3i d\u00e2y treo kh\u00f4ng d\u00e3n c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng kh\u00f4ng \u0111\u00e1ng k\u1ec3, chi\u1ec1u 0,1m \u0111\u01b0\u1ee3c treo th\u1eb3ng \u0111\u1ee9ng. Bi\u1ebft con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, t\u1ea1i v\u1ecb tr\u00ed li \u0111\u1ed9 g\u00f3c 0,075 rad th\u00ec c\u00f3 v\u1eadn t\u1ed1c 0,075 3 m\/s. Cho gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=10m\/s2. T\u00ednh c\u01a1 n\u0103ng c\u1ee7a dao \u0111\u1ed9ng A. 4,7 mJ B. 4,4 mJ C. 4,5 mJ D. 4,8 mJ C\u00e2u 48: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m m\u1ed9t vi\u00ean bi nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng 100g \u0111\u01b0\u1ee3c treo \u1edf \u0111\u1ea7u m\u1ed9t s\u1ee3i d\u00e2y d\u00e0i 1,57m t\u1ea1i n\u01a1i c\u00f3 g=9,81m\/s2. K\u00e9o con l\u1eafc l\u1ec7ch kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t g\u00f3c 0,1 rad r\u1ed3i th\u1ea3 cho n\u00f3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a kh\u00f4ng v\u1eadn t\u1ed1c ban \u0111\u1ea7u. T\u00ednh \u0111\u1ed9ng n\u0103ng c\u1ee7a vi\u00ean bi khi g\u00f3c l\u1ec7ch c\u1ee7a n\u00f3 l\u00e0 0,05rad: A. 0,00195J B. 0,00585J C. 0,00591J D. 0,00577J TRANG 77","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 49: Con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03c0\/20 (rad) t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2. L\u1ea5y \u03c02=10. Th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 con l\u1eafc \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng \u0111\u1ebfn v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 g\u00f3c \u03c0 2 \/40 (rad) A. 1\/3 s B. 1\/4s C. 3s D. 3 2 s C\u00e2u 50: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng nh\u1ecf v\u1edbi bi\u00ean \u0111\u1ed9 d\u00e0i 4cm. Kho\u1ea3ng th\u1eddi gian gi\u1eefa hai l\u1ea7n li\u00ean ti\u1ebfp v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt \u0111\u1ea1t gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i l\u00e0 0,05s. Kho\u1ea3ng th\u1eddi gian ng\u1eafn nh\u1ea5t \u0111\u1ec3 n\u00f3 \u0111i t\u1eeb v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 s1=2cm \u0111\u1ebfn li \u0111\u1ed9 s2=4cm l\u00e0: A. 1\/60s B. 1\/120s C. 1\/80s D. 0,01s C\u00e2u 51: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b10=50. V\u1edbi li \u0111\u1ed9c g\u00f3c \u03b1 b\u1eb1ng bao nhi\u00eau th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc g\u1ea5p 2 l\u1ea7n th\u1ebf n\u0103ng: A. \uf061 = \uf0b13, 450 B. \uf061 = 2,890 C. \uf061 = \uf0b12,890 D. \uf061 = 3, 450 C\u00e2u 52: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i = 1m \u0111\u01b0\u1ee3c k\u00edch th\u00edch dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 = \uf0702 m\/s2. Ban \u0111\u1ea7u \u0111\u01b0a v\u1eadt \u0111\u1ebfn v\u1ecb tr\u00ed d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 = 0,02 rad r\u1ed3i th\u1ea3 nh\u1eb9. K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, v\u1eadt \u0111i qua v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng 3 l\u1ea7n th\u1ebf n\u0103ng l\u1ea7n th\u1ee9 2020 v\u00e0o th\u1eddi \u0111i\u1ec3m 3029 3031 3029 3029 A. s. B. s. C. s. D. s. 2 3 5 4 C\u00e2u 53: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b10. Con l\u1eafc c\u00f3 th\u1ebf n\u0103ng b\u1eb1ng \u0111\u1ed9ng n\u0103ng c\u1ee7a n\u00f3 kh\u00ed v\u1eadt qua v\u1ecb tr\u00ed c\u00f3 li \u0111\u1ed9 g\u00f3c: A. \uf061 = \uf0b1 \uf061o B. \uf061 = \uf0b1 \uf061o C. \uf061 = \uf0b1 \uf061o D. \uf061 = \uf0b1 \uf061o 22 2 4 2 C\u00e2u 54: T\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g, m\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1o nh\u1ecf. L\u1ea5y m\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi con l\u1eafc chuy\u1ec3n \u0111\u1ed9ng nhanh d\u1ea7n theo chi\u1ec1u d\u01b0\u01a1ng \u0111\u1ebfn v\u1ecb tr\u00ed c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng th\u1ebf n\u0103ng th\u00ec li \u0111\u1ed9 g\u00f3c \u03b1 c\u1ee7a con l\u1eafc b\u1eb1ng A. \uf0610 B. \uf0610 C. \u2212 \uf0610 D. \u2212 \uf0610 3 2 2 3 C\u00e2u 55: T\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g, m\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1o nh\u1ecf. L\u1ea5y m\u1ed1c th\u1ebf n\u0103ng \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Khi con l\u1eafc chuy\u1ec3n \u0111\u1ed9ng ch\u1eadm d\u1ea7n theo chi\u1ec1u d\u01b0\u01a1ng \u0111\u1ebfn v\u1ecb tr\u00ed c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng 1\/3 l\u1ea7n th\u1ebf n\u0103ng th\u00ec li \u0111\u1ed9 g\u00f3c \u03b1 c\u1ee7a CL\u0110 b\u1eb1ng: A. \u2212 \uf0610 B. \uf061o 3 C. \u2212 \uf061o 3 D. \uf0610 2 2 2 2 C\u00e2u 56: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m d\u00e2y treo c\u00f3 chi\u1ec1u d\u00e0i 1m v\u00e0 v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m \u0111\u01b0\u1ee3c k\u00edch th\u00edch dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 = \uf0702 m\/s2. Bi\u1ebft l\u1ef1c k\u00e9o v\u1ec1 c\u1ef1c \u0111\u1ea1i t\u00e1c d\u1ee5ng l\u00ean v\u1eadt n\u1eb7ng v\u00e0 n\u0103ng l\u01b0\u1ee3ng c\u1ee7a dao \u0111\u1ed9ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 F=2N v\u00e0 W=30mJ. Ch\u1ecdn g\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt \u0111i qua v\u1ecb tr\u00ed \u0111\u1ed9ng n\u0103ng b\u1eb1ng ba l\u1ea7n th\u1ebf n\u0103ng theo chi\u1ec1u d\u01b0\u01a1ng v\u00e0 th\u1ebf n\u0103ng c\u1ee7a v\u1eadt \u0111ang t\u0103ng. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 A. \uf061 = 0,3cos \uf0e6 \uf070t \u2212 \uf070\uf0f6 rad. B. \uf061 = 0, 03 cos \uf0e6 2\uf070t + \uf070 \uf0f6 rad. \uf0e7\uf0e8 4 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 C. \uf061 = 0,03cos\uf0e6\uf0e7\uf0e8 \uf070t \u2212 \uf070\uf0f6 rad. D. \uf061 = 0, 3cos \uf0e6 \uf070t \u2212 \uf070\uf0f6 rad. 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 TRANG 78","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 57: (Tam Hi\u1ec7p \u2013 2018) T\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 9,8 m\/s2, m\u1ed9t con l\u1eafc \u0111\u01a1n \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \uf0610 = 70 . Bi\u1ebft kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt nh\u1ecf c\u1ee7a con l\u1eafc l\u00e0 m=95 g v\u00e0 chi\u1ec1u d\u00e0i d\u00e2y treo l\u00e0 1,5 m. Ch\u1ecdn m\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, c\u01a1 n\u0103ng c\u1ee7a con l\u1eafc c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y? A. 10 mJ. B. 9 J. C. 10 J. D. 9 mJ. C\u00e2u 58: (S\u1edf T\u00e2y Ninh \u2013 2019) M\u1ed9t con l\u1eafc \u0111\u01a1n d\u00e0i 2,0 m c\u00f3 v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng 500 g \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c r\u01a1i t\u1ef1 do 10 m\/s2. Khi \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt l\u00e0 4,5 mJ th\u00ec \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c k\u00e9o v\u1ec1 l\u00e0 0,20 N. Khi \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt l\u00e0 8 mJ th\u00ec \u0111\u1ed9 l\u1edbn c\u1ee7a l\u1ef1c k\u00e9o v\u1ec1 l\u00e0 A. 0,15 N. B. 2 N. C. 0 N. D. 1 N. C\u00e2u 59: T\u1ea1i c\u00f9ng m\u1ed9t n\u01a1i tr\u00ean Tr\u00e1i \u0110\u1ea5t, c\u00f3 hai con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi c\u00f9ng bi\u00ean \u0111\u1ed9 g\u00f3c \uf0610 = 0,05 rad. G\u1ecdi F1, F2 v\u00e0 m1, m2 l\u1ea7n l\u01b0\u1ee3t l\u00e0 l\u1ef1c k\u00e9o v\u1ec1 c\u1ef1c \u0111\u1ea1i t\u00e1c d\u1ee5ng l\u00ean con l\u1eafc v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a c\u00e1c con l\u1eafc. Bi\u1ebft r\u1eb1ng F1 = 4F2 v\u00e0 m1 + m2 = 5 kg. L\u1ea5y g = 10 m\/s2 v\u00e0 chi\u1ec1u d\u00e0i c\u1ee7a c\u00e1c con l\u1eafc l\u00e0 1m. N\u0103ng l\u01b0\u1ee3ng dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t l\u00e0 A. 1 J. B. 0,7 J. C. 0,6 J. D. 0,05 J. C\u00e2u 60: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m qu\u1ea3 c\u1ea7u c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100 (g), t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10 m\/s2. K\u00e9o con l\u1eafc l\u1ec7ch kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t g\u00f3c 0,1 rad r\u1ed3i th\u1ea3 nh\u1eb9. Khi v\u1eadt qua v\u1ecb tr\u00ed c\u00f3 t\u1ed1c \u0111\u1ed9 b\u1eb1ng n\u1eeda t\u1ed1c \u0111\u1ed9 c\u1ef1c \u0111\u1ea1i th\u00ec l\u1ef1c k\u00e9o v\u1ec1 c\u00f3 \u0111\u1ed9 l\u1edbn l\u00e0 A. 0,087 N. B. 0,1 N. C. 0,025 N. D. 0,05 N. C\u00e2u 61: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m qu\u1ea3 c\u1ea7u c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 200 (g) d\u00e2y d\u00e0i 0,5 m, t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10 m\/s2. K\u00e9o con l\u1eafc l\u1ec7ch kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t g\u00f3c r\u1ed3i th\u1ea3 nh\u1eb9 th\u00ec n\u00f3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. Khi v\u1eadt \u1edf li \u0111\u1ed9 b\u1eb1ng 3 cm th\u00ec l\u1ef1c k\u00e9o v\u1ec1 c\u00f3 \u0111\u1ed9 l\u1edbn l\u00e0 A. 2,12 N. B. 2N. C. 0,12 N. D. 2,06 N. C\u00e2u 62: Con l\u1eafc \u0111\u01a1n \u0111\u01b0\u1ee3c k\u00edch th\u00edch \u0111\u1ec3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 m\/s2. Quan s\u00e1t dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc th\u00ec th\u1ea5y r\u1eb1ng khi d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 = 0,02 rad th\u00ec l\u1ef1c k\u00e9o v\u1ec1 t\u00e1c d\u1ee5ng l\u00ean v\u1eadt n\u1eb7ng c\u1ee7a con l\u1eafc Fkv = 0,04 N. Kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt n\u1eb7ng: A. 100 g. B. 200 g. C. 300 g. D. 400 g. C\u00e2u 63: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=200g \u0111\u01b0\u1ee3c k\u00edch th\u00edch dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g = 10 m\/s2. Ban \u0111\u1ea7u \u0111\u01b0a v\u1eadt \u0111\u1ebfn v\u1ecb tr\u00ed d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 = 0,01 rad r\u1ed3i truy\u1ec1n cho v\u1eadt m\u1ed9t v\u1eadn t\u1ed1c v = 30 cm\/s theo ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi d\u00e2y treo. Ch\u1ecdn g\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, t\u00ednh c\u01a1 n\u0103ng c\u1ee7a con l\u1eafc: A. 4 mJ. B. 15 mJ. C. 0,4 mJ. D. 0,34 mJ. C\u00e2u 64: (\u0110H-2017) \u1ede m\u1ed9t n\u01a1i tr\u00ean Tr\u00e1i \u0110\u1ea5t, hai con l\u1eafc \u0111\u01a1n c\u00f3 c\u00f9ng chi\u1ec1u d\u00e0i \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi c\u00f9ng bi\u00ean \u0111\u1ed9. G\u1ecdi m1, F1 v\u00e0 m2, F2 l\u1ea7n l\u01b0\u1ee3t l\u00e0 kh\u1ed1i l\u01b0\u1ee3ng, \u0111\u1ed9 l\u1edbn l\u1ef1c k\u00e9o v\u1ec1 c\u1ef1c \u0111\u1ea1i c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t v\u00e0 con l\u1eafc th\u1ee9 hai. Bi\u1ebft m1 + m2=1,2kg v\u00e0 2F2=3F1. T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a m1 l\u00e0: A. 720g B. 400g C. 480g D. 600g C\u00e2u 65: (\u0110H-2017) \u1ede m\u1ed9t n\u01a1i tr\u00ean Tr\u00e1i \u0110\u1ea5t, hai con l\u1eafc \u0111\u01a1n c\u00f3 c\u00f9ng kh\u1ed1i l\u01b0\u1ee3ng \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. G\u1ecdi 1, s01, F1 v\u00e0 2, s02, F2 l\u1ea7n l\u01b0\u1ee3t l\u00e0 chi\u1ec1u d\u00e0i, bi\u00ean \u0111\u1ed9, \u0111\u1ed9 l\u1edbn l\u1ef1c k\u00e9o v\u1ec1 c\u1ef1c \u0111\u1ea1i c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t v\u00e0 con l\u1eafc th\u1ee9 hai. Bi\u1ebft 3 2=2 1, 2s02=3s01. T\u1ef7 s\u1ed1 F1 F2 A. 4 B. 3 C. 9 D. 2 9 243 TRANG 79","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 4: L\u1ef0C C\u0102NG D\u00c2Y- V\u1eacN T\u1ed0C-GIA T\u1ed0C C\u1ee6A CON L\u1eaeC \u0110\u01a0N V\u1eadn T\u1ed1c Gia t\u1ed1c L\u1ef1c c\u0103ng d\u00e2y V\u1ecb tr\u00ed b\u1ea5t k\u00ec v = 2g (cos \uf061 \u2212 cos \uf061o ) a = a tt2 + a ht2 T = mg(3cos \uf061 \u2212 2 cos \uf061o ) VTCB (\u03b1=0) vmax = 2g (1 \u2212 cos \uf061o ) a VTCB = aht = v2 Tmax = mg(3 \u2212 2 cos \uf061o ) VTB (\u03b1=\u03b1o) vmax = So .w = \uf061o. g max Tmin = mg cos \uf061o v = vmin = 0 a VTB = a tt = w 2.So T\u1ec9 s\u1ed1 a VTCB = \uf061o Tmax = 3 \u2212 2 cos \uf061o a VTB Tmin cos \uf061o C\u00e2u 66: Ph\u00e1t bi\u1ec3u n\u00e0o sau \u0111\u00e2y l\u00e0 sai khi n\u00f3i v\u1ec1 dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc \u0111\u01a1n A. Khi v\u1eadt n\u1eb7ng \u1edf v\u1ecb tr\u00ed bi\u00ean, c\u01a1 n\u0103ng c\u1ee7a con l\u1eafc b\u1eb1ng th\u1ebf n\u0103ng c\u1ee7a n\u00f3 B. Chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a con l\u1eafc t\u1eeb v\u1ecb tr\u00ed bi\u00ean v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u00e0 nhanh d\u1ea7n C. Khi v\u1eadt n\u1eb7ng \u0111i qua VTCB th\u00ec tr\u1ecdng l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean n\u00f3 c\u00e2n b\u1eb1ng v\u1edbi l\u1ef1c c\u0103ng c\u1ee7a d\u00e2y D. V\u1edbi dao \u0111\u1ed9ng nh\u1ecf th\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc \u0111\u01a1n l\u00e0 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a C\u00e2u 67: C\u00e2u tr\u1ea3 l\u1eddi n\u00e0o l\u00e0 \u0111\u00fang khi n\u00f3i v\u1ec1 l\u1ef1c c\u0103ng c\u1ee7a d\u00e2y treo con l\u1eafc \u0111\u01a1n: A. Nh\u01b0 nhau t\u1ea1i m\u1ecdi v\u1ecb tr\u00ed B. L\u1edbn nh\u1ea5t t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 l\u1edbn h\u01a1n tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a con l\u1eafc C. L\u1edbn nh\u1ea5t \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 nh\u1ecf h\u01a1n tr\u1ecdng l\u01b0\u1ee3ng c\u1ee7a con l\u1eafc D. Nh\u1ecf nh\u1ea5t t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 b\u1eb1ng tr\u1ecdng l\u1ef1c con l\u1eafc C\u00e2u 68: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 43,2cm, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m dao \u0111\u1ed9ng \u1edf n\u01a1i c\u00f3 gia t\u00f3c tr\u1ecdng tr\u01b0\u1eddng g=10m\/s2 v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1o, sao cho l\u1ef1c c\u0103ng d\u00e2y c\u1ef1c \u0111\u1ea1i g\u1ea5p 4 l\u1ea7n l\u1ef1c c\u0103ng d\u00e2y c\u1ef1c ti\u1ec3u. Khi l\u1ef1c c\u0103ng d\u00e2y b\u1eb1ng 2 l\u1ea7n l\u1ef1c c\u0103ng c\u1ef1c ti\u1ec3u th\u00ec t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0: A. 1m\/s B. 1,2 m\/s C. 1,6 m\/s D. 2m\/s C\u00e2u 69: M\u1ed9t v\u1eadt nh\u1ecf \u0111\u01b0\u1ee3c treo v\u00e0o m\u1ed9t s\u1ee3i d\u00e2y kh\u00f4ng gi\u00e3n, kh\u00f4ng kh\u1ed1i l\u01b0\u1ee3ng \u0111\u1ec3 t\u1ea1o th\u00e0nh m\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l = 1 m. V\u1eadt n\u1eb7ng \u0111ang \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec \u0111\u01b0\u1ee3c k\u00e9o \u0111\u1ebfn v\u1ecb tr\u00ed m\u00e0 d\u00e2y treo l\u00e0m v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 600 r\u1ed3i th\u1ea3 nh\u1eb9. B\u1ecf qua m\u1ecdi l\u1ef1c c\u1ea3n, l\u1ea5y g = 10 m\/s2. Trong qu\u00e1 tr\u00ecnh chuy\u1ec3n \u0111\u1ed9ng, t\u1ea1i v\u1ecb tr\u00ed m\u00e0 d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 v\u1edbi cos \uf061 = 5 6 th\u00ec t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt n\u1eb7ng g\u1ea7n b\u1eb1ng A. 2,6 m\/s. B. 6,7 m\/s. C. 1,8 m\/s. D. 2,9 m\/s. C\u00e2u 70: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i d\u00e2y treo 100 cm, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m dao \u0111\u1ed9ng \u1edf n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng coi g\u1ea7n \u0111\u00fang b\u1eb1ng 10 m\/s2 v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c sao cho l\u1ef1c c\u0103ng s\u1ee3i d\u00e2y c\u1ef1c \u0111\u1ea1i g\u1ea5p 3 l\u1ea7n l\u1ef1c c\u0103ng c\u1ef1c ti\u1ec3u. Khi l\u1ef1c c\u0103ng s\u1ee3i d\u00e2y g\u1ea5p \u0111\u00f4i gi\u00e1 tr\u1ecb c\u1ef1c ti\u1ec3u th\u00ec t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt l\u00e0 A. 1 m\/s. B. 1,2 m\/s. C. 1,5 m\/s. D. 2 m\/s. C\u00e2u 71: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 6o. T\u1ef7 s\u1ed1 gi\u1eefa l\u1ef1c c\u0103ng d\u00e2y v\u00e0 tr\u1ecdng l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean qu\u1ea3 c\u1ea7u \u1edf v\u1ecb tr\u00ed cao nh\u1ea5t l\u00e0: A. 0,96 B. 0,994 C. 0,995 D. 1,052 C\u00e2u 72: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng kh\u00f4ng ma s\u00e1t t\u1ea1i m\u1ed9t n\u01a1i nh\u1ea5t \u0111\u1ecbnh d\u00e2y treo d\u00e0i 0,5m, kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt n\u0103ng 100g, dao \u0111\u1ed9ng t\u1ea1i n\u01a1i c\u00f3 g=9,8 m\/s2. T\u1ef7 s\u1ed1 gi\u1eefa l\u1ef1c c\u0103ng d\u00e2y c\u1ef1c \u0111\u1ea1i v\u00e0 c\u1ef1c ti\u1ec3u c\u1ee7a d\u00e2y treo l\u00e0 4. C\u01a1 n\u0103ng dao \u0111\u1ed9ng b\u1eb1ng A. 0,245J B. 2,45J C. 1,225J D. 0,1225J TRANG 80","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 73: Con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng kh\u00f4ng ma s\u00e1t, s\u1ee3i d\u00e2y d\u00e0i 30cm, v\u1eadt dao \u0111\u1ed9ng n\u1eb7ng 100g, g=10m\/s2. Khi v\u1eadt dao \u0111\u1ed9ng qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec l\u1ef1c t\u1ed5ng h\u1ee3p t\u00e1c d\u1ee5ng l\u00ean v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn 1N. T\u00ednh t\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt dao \u0111\u1ed9ng khi l\u1ef1c c\u0103ng d\u00e2y c\u00f3 \u0111\u1ed9 l\u1edbn g\u1ea5p \u0111\u00f4i \u0111\u1ed9 l\u1edbn c\u1ef1c ti\u1ec3u c\u1ee7a n\u00f3: A. 0,5m\/s B. 1m\/s C. 1,4 m\/s D. 2m\/s C\u00e2u 74: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 \u03b10 t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng l\u00e0 g. Bi\u1ebft l\u1ef1c c\u0103ng d\u00e2y l\u1edbn nh\u1ea5t b\u1eb1ng 1,02 l\u1ea7n l\u1ef1c c\u0103ng d\u00e2y nh\u1ecf nh\u1ea5t. Gi\u00e1 tr\u1ecb c\u1ee7a \u03b1o l\u00e0: A. 3,3o B. 6,6o C. 5,6o D. 9,6o C\u00e2u 75: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m m\u1ed9t v\u1eadt nh\u1ecf \u0111\u01b0\u1ee3c treo v\u00e0o \u0111\u1ea7u d\u01b0\u1edbi c\u1ee7a m\u1ed9t s\u1ee3i d\u00e2y kh\u00f4ng d\u00e3n, \u0111\u1ea7u tr\u00ean c\u1ee7a s\u1ee3i d\u00e2y \u0111\u01b0\u1ee3c bu\u1ed9c c\u1ed1 \u0111\u1ecbnh. B\u1ecf qua ma s\u00e1t v\u00e0 l\u1ef1c c\u1ea3n c\u1ee7a kh\u00f4ng kh\u00ed. K\u00e9o con l\u1eafc l\u1ec7ch kh\u1ecfi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c 0,1 rad r\u1ed3i th\u1ea3 nh\u1eb9. T\u1ef7 s\u1ed1 gi\u1eefa \u0111\u1ed9 l\u1edbn gia t\u1ed1c c\u1ee7a v\u1eadt t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng v\u00e0 \u0111\u1ed9 l\u1edbn gia t\u1ed1c t\u1ea1i v\u1ecb tr\u00ed bi\u00ean b\u1eb1ng: A. 0,1 B. 0 C. 10 D. 5,73 C\u00e2u 76: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m, dao \u0111\u1ed9ng t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2. G\u00f3c l\u1edbn nh\u1ea5t m\u00e0 d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng l\u00e0 \u03b1o=0,1 rad. T\u1ea1i v\u1ecb tr\u00ed d\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng 1 g\u00f3c \u03b1=0,01rad th\u00ec gia t\u1ed1c c\u1ee7a con l\u1eafc l\u00e0: A. 0,1 m\/s2 B. 0,0989 m\/s2 C. 0,17 m\/s2 D. 0,14 m\/s2 C\u00e2u 77: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m m\u1ed9t qu\u1ea3 c\u1ea7u nh\u1ecf, kh\u1ed1i l\u01b0\u1ee3ng 0,05 kg treo v\u00e0o \u0111\u1ea7u m\u1ed9t s\u1ee3i d\u00e2y d\u00e0i 1 m, \u1edf n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 9,81 m\/s2. B\u1ecf qua ma s\u00e1t. Con l\u1eafc dao \u0111\u1ed9ng theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi g\u00f3c l\u1ec7ch c\u1ef1c \u0111\u1ea1i so v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng l\u00e0 30\u00b0. T\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt v\u00e0 l\u1ef1c c\u0103ng d\u00e2y khi qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u00e0 A. 1,62 m\/s v\u00e0 0,62 N. B. 2,63 m\/s v\u00e0 0,62 N. C. 4,12 m\/s v\u00e0 1,34 N. D. 0,412 m\/s v\u00e0 13,4 N. C\u00e2u 78: M\u1ed9t con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi \u0111\u1ed9ng n\u0103ng c\u1ef1c \u0111\u1ea1i b\u1eb1ng 1,28mJ t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=9,8 m\/s2. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, \u0111\u1ed9 l\u1edbn l\u1ef1c c\u0103ng d\u00e2y c\u1ef1c \u0111\u1ea1i v\u00e0 l\u1ef1c c\u0103ng d\u00e2y c\u1ef1c ti\u1ec3u h\u01a1n k\u00e9m nhau 9,6.10-3N. Chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: A. 1,59s B. 2,01s C. 1,27s D. 3,17s TRANG 81","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 5: CON L\u1eaeC \u0110\u01a0N CH\u1ecaU TH\u00caM T\u00c1C D\u1ee4NG C\u1ee6A NGO\u1ea0I L\u1ef0C L\u1ef0C \u0110I\u1ec6N TR\u01af\u1edcNG L\u1ef0C QU\u00c1N T\u00cdNH \uf0ec \u2192\u2192 \u2192\u2192 \u2192 \u2192 \uf0efNe\u00e1u q \uf03e 0 : F\u0111 \uf0ad\uf0ad E \u2756 Bi\u1ec3u th\u1ee9c: \uf0ed \u2756 Bi\u1ec3u th\u1ee9c: Fq = \u2212m a F\u0111 = q.E \uf0ee\uf0efNe\u00e1u \u2192\u2192 (L\u1ef1c qu\u00e1n t\u00ednh lu\u00f4n ng\u01b0\u1ee3c chi\u1ec1u v\u1edbi gia t\u1ed1c) q \uf03c 0 : F\u0111 \uf0ad\uf0af E \u2756 \u0110\u1ed9 l\u1edbn: Fq= m.a \u2756 C\u00e1ch nh\u1eadn bi\u1ebft: L\u1ef1c qu\u00e1n t\u00ednh xu\u1ea5t hi\u1ec7n khi \u2756 \u0110\u1ed9 l\u1edbn: F\u00f1 = q .E CL\u0110 \u0111\u01b0\u1ee3c treo trong thang m\u00e1y ho\u1eb7c \u00f4 t\u00f4 \u0111ang chuy\u1ec3n \u0111\u1ed9ng bi\u1ebfn \u0111\u1ed5i \u0111\u1ec1u v\u1edbi \u0111\u1ed9 l\u1edbn gia t\u1ed1c a. \u2756 C\u00e1ch nh\u1eadn bi\u1ebft: L\u1ef1c \u0111i\u1ec7n tr\u01b0\u1eddng xu\u1ea5t hi\u1ec7n khi Ngo\u1ea1i l\u1ef1c c\u00f3 ph\u01b0\u01a1ng n\u1eb1m ngang CL\u0110 mang \u0111i\u1ec7n t\u00edch \u0111\u1eb7t trong m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u C\u00e1c Ngo\u1ea1i l\u1ef1c c\u00f3 ph\u01b0\u01a1ng th\u1eb3ng tr\u01b0\u1eddng \u0111\u1ee9ng h\u1ee3p Treo trong thang Con l\u1eafc c\u00f3 \u0111i\u1ec7n t\u00edch Treo trong \u00f4 t\u00f4 Con l\u1eafc c\u00f3 \u0111i\u1ec7n t\u00edch q \u0111\u1eb7t c\u1ee7a m\u00e1y chuy\u1ec3n q \u0111\u1eb7t trong \u0111i\u1ec7n chuy\u1ec3n \u0111\u1ed9ng B\u0110\u0110 trong \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u E c\u00f3 ngo\u1ea1i tr\u01b0\u1eddng \u0111\u1ec1u E c\u00f3 l\u1ef1c \u0111\u1ed9ng B\u0110\u0110 v\u1edbi theo ph\u01b0\u01a1ng ph\u01b0\u01a1ng n\u1eb1m ngang gia t\u1ed1c a. ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. ngang v\u1edbi gia t\u1ed1c a D\u00e2y treo h\u1ee3p v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng 1 g\u00f3c \u03b1 VTCB Tr\u00f9ng v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng tan \uf061 = Fqt = a tan \uf061 = F\u0111 = q .E Pg P m.g Chu T = 2\uf070 T = 2\uf070 \uf0e6 q .E \uf0f62 k\u00ec T = 2\uf070 q .E g2 + \uf0e7\uf0e7\uf0e8 m \uf0f7\uf0f7\uf0f8 T = 2\uf070 g\uf0b1a g\uf0b1 g2 + a2 m KI\u1ec2U 1: NGO\u1ea0I L\u1ef0C C\u00d3 PH\u01af\u01a0NG TH\u1eb2NG \u0110\u1ee8NG C\u00e2u 79: M\u1ed9t con l\u1eafc \u0111\u01a1n, kh\u1ed1i l\u01b0\u1ee3ng m=100g, treo trong m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng xu\u1ed1ng d\u01b0\u1edbi, c\u00f3 \u0111\u1ed9 l\u1edbn E=9800V\/m. Khi ch\u01b0a t\u00edch \u0111i\u1ec7n th\u00ec con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chu k\u00ec l\u00e0 2s t\u1ea1i n\u01a1i c\u00f3 tr\u1ecdng tr\u01b0\u1eddng g=9,8m\/s2. Truy\u1ec1n cho qu\u1ea3 n\u1eb7ng \u0111i\u1ec7n t\u00edch q > 0 th\u00ec chu k\u00ec dao \u0111\u1ed9ng nh\u1ecf c\u1ee7a n\u00f3 thay \u0111\u1ed5i 0,02s. Gi\u00e1 tr\u1ecb q b\u1eb1ng A. 0,2\u03bcC B. 3 \u03bcC C. 0,3 \u03bcC D. 2 \u03bcC C\u00e2u 80: M\u1ed9t con l\u1eafc \u0111\u01a1n treo v\u00e0o tr\u1ea7n m\u1ed9t thang m\u00e1y, khi thang m\u00e1y c\u00f3 gia t\u1ed1c kh\u00f4ng \u0111\u1ed5i q th\u00ec chu k\u00ec con l\u1eafc t\u0103ng 8,46% so v\u1edbi chu k\u00ec c\u1ee7a n\u00f3 khi thang m\u00e1y \u0111\u1ee9ng y\u00ean, g=10m\/s2. X\u00e1c \u0111\u1ecbnh chi\u1ec1u v\u00e0 \u0111\u1ed9 l\u1edbn gia t\u1ed1c a A. H\u01b0\u1edbng l\u00ean tr\u00ean v\u00e0 \u0111\u1ed9 l\u1edbn l\u00e0 1,5m\/s2 B. H\u01b0\u1edbng l\u00ean tr\u00ean v\u00e0 \u0111\u1ed9 l\u1edbn l\u00e0 2m\/s2 C. H\u01b0\u1edbng xu\u1ed1ng d\u01b0\u1edbi v\u00e0 \u0111\u1ed9 l\u1edbn l\u00e0 2m\/s2 D. H\u01b0\u1edbng xu\u1ed1ng d\u01b0\u1edbi v\u00e0 \u0111\u1ed9 l\u1edbn l\u00e0 1,5m\/s2 C\u00e2u 81: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng qu\u1ea3 c\u1ea7u b\u1eb1ng 200 g, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 nh\u1ecf c\u00f3 chu k\u00ec To, t\u1ea1i m\u1ed9t n\u01a1i c\u00f3 gia t\u1ed1c g = 10 m\/s2, t\u00edch \u0111i\u1ec7n cho qu\u1ea3 c\u1ea7u q = \u22124.10\u22124 C r\u1ed3i cho n\u00f3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a trong m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng th\u00ec th\u1ea5y chu k\u00ec c\u1ee7a con l\u1eafc t\u0103ng l\u00ean g\u1ea5p 2 l\u1ea7n. Vecto c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng c\u00f3 A. chi\u1ec1u h\u01b0\u1edbng xu\u1ed1ng v\u00e0 E = 7,5.103 V\/m. B. chi\u1ec1u h\u01b0\u1edbng l\u00ean v\u00e0 E = 7,5.103 V\/m. C. chi\u1ec1u h\u01b0\u1edbng xu\u1ed1ng v\u00e0 E = 3,75.103 V\/m. D. chi\u1ec1u h\u01b0\u1edbng l\u00ean v\u00e0 E = 3,75.103 V\/m. TRANG 82","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 82: M\u1ed9t con l\u1eafc \u0111\u01a1n l\u00fd t\u01b0\u1edfng, m=500g, dao \u0111\u1ed9ng t\u1ea1i n\u01a1i c\u00f3 g=10m\/s2, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T0. Khi t\u00edch \u0111i\u1ec7n cho qu\u1ea3 c\u1ea7u v\u1edbi \u0111i\u1ec7n t\u00edch q= -5.10-5C, tr\u1ecdng \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u c\u00f3 v\u00e9c t\u01a1 E th\u1eb3ng \u0111\u1ee9ng th\u00ec con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chu k\u00ec T1. Bi\u1ebft T1 = 10 . X\u00e1c \u0111\u1ecbnh v\u00e9c \u2013t\u01a1 c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng To 11 A. H\u01b0\u1edbng l\u00ean tr\u00ean v\u00e0 E=10000V\/m B. H\u01b0\u1edbng l\u00ean tr\u00ean v\u00e0 E=100V\/m C. H\u01b0\u1edbng xu\u1ed1ng d\u01b0\u1edbi v\u00e0 E=10000V\/m D. H\u01b0\u1edbng xu\u1ed1ng d\u01b0\u1edbi v\u00e0 E=100V\/m C\u00e2u 83: M\u1ed9t con l\u1eafc \u0111\u01a1n \u0111\u01b0\u1ee3c treo v\u00e0o tr\u1ea7n m\u1ed9t thang m\u00e1y. Khi thang m\u00e1y chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng \u0111\u1ee9ng \u0111i l\u00ean nhanh d\u1ea7n \u0111\u1ec1u v\u1edbi gia t\u1ed1c a th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 2,52s. Khi thang m\u00e1y chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng \u0111\u1ee9ng \u0111i l\u00ean ch\u1eadm d\u1ea7n \u0111\u1ec1u v\u1edbi gia t\u1ed1c c\u0169ng c\u00f3 \u0111\u1ed9 l\u1edbn a th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 3,15s. Khi thang m\u00e1y \u0111\u1ee9ng y\u00ean th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. 2,78s B. 2,96s C. 2,61s D. 2,84s C\u00e2u 84: M\u1ed9t con l\u1eafc \u0111\u01a1n ban \u0111\u1ea7u dao \u0111\u1ed9ng v\u1edbi chu k\u00ec T. Khi t\u00edch \u0111i\u1ec7n t\u00edch q1 th\u00ec con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chu k\u00ec T1=2T, c\u00f2n khi t\u00edch \u0111i\u1ec7n q2 th\u00ec con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chu k\u00ec T2= 2 T. Bi\u1ebft v\u00e9c t\u01a1 c\u01b0\u1eddng 5 \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng th\u1eb3ng \u0111\u1ee9ng h\u01b0\u1edbng l\u00ean. T\u00ednh t\u1ef7 s\u1ed1 q1 \/ q2 : A. -3 B. 3 C. 2 D. -2 C\u00e2u 85: Hai con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l v\u00e0 l\uf0a2 = l + 7,9 cm c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng hai v\u1eadt n\u1eb7ng t\u01b0\u01a1ng \u1ee9ng m = m\uf0a2 = 2 g, v\u1eadt m kh\u00f4ng mang \u0111i\u1ec7n c\u00f2n v\u1eadt m\uf0a2 c\u00f3 \u0111i\u1ec7n t\u00edch q = 0,5.10\u22128 C. Khi cho hai v\u1eadt dao \u0111\u1ed9ng t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c r\u01a1i t\u1ef1 do g = 9,8 m\/s2 th\u00ec trong kho\u1ea3ng th\u1eddi gian \uf044t con l\u1eafc l th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 40 dao \u0111\u1ed9ng v\u00e0 con l\u1eafc l\uf0a2 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c 30 dao \u0111\u1ed9ng. Khi xu\u1ea5t hi\u1ec7n \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u E c\u00f3 \u0111\u01b0\u1eddng s\u1ee9c th\u1eb3ng \u0111\u1ee9ng h\u01b0\u1edbng xu\u1ed1ng th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a hai con l\u1eafc l\u00e0 nh\u01b0 nhau. \u0110\u1ed9 l\u1edbn c\u1ee7a c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng E g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y? A. 1,6.105 V\/m. B. 1,96.105 V\/m. C. 2.105 V\/m. D. 5, 2.106 V\/m. C\u00e2u 86: (\u0110\u1ec1 Thi Th\u1eed-2018) Hai con l\u1eafc \u0111\u01a1n c\u00f3 c\u00f9ng chi\u1ec1u d\u00e0i d\u00e2y treo, v\u1eadt n\u1eb7ng c\u00f3 c\u00f9ng kh\u1ed1i l\u01b0\u1ee3ng \u2192 nh\u01b0ng mang \u0111i\u1ec7n t\u00edch l\u1ea7n l\u01b0\u1ee3t l\u00e0 q1, q2. Ch\u00fang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a trong \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u E h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng xu\u1ed1ng, t\u1ea1i c\u00f9ng m\u1ed9t n\u01a1i x\u00e1c \u0111\u1ecbnh, chu k\u00ec l\u1ea7n l\u01b0\u1ee3t l\u00e0 0,5s v\u00e0 0,3s. Khi t\u1eaft \u0111i\u1ec7n tr\u01b0\u1eddng th\u00ec hai con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chu k\u00ec 0,4s. T\u1ef7 s\u1ed1 q1\/q2 l\u00e0: A. \u221281 B. \u22127 C. 175 D. 9 175 9 81 7 C\u00e2u 87: (\u0110\u1ec1 Thi Th\u1eed-2018) M\u1ed9t con l\u1eafc \u0111\u01a1n \u0111\u01b0\u1ee3c treo v\u00e0o tr\u1ea7n m\u1ed9t thang m\u00e1y. Khi thang m\u00e1y chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng \u0111\u1ee9ng \u0111i l\u00ean nhanh d\u1ea7n \u0111\u1ec1u v\u1edbi gia t\u1ed1c c\u00f3 \u0111\u1ed9 l\u1edbn a th\u00ec chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00e0 2,15s. Khi thang m\u00e1y chuy\u1ec3n \u0111\u1ed9ng th\u1eb3ng \u0111\u1ee9ng \u0111i l\u00ean ch\u1eadm d\u1ea7n \u0111\u1ec1u v\u1edbi gia t\u1ed1c c\u0169ng c\u00f3 \u0111\u1ed9 l\u1edbn a th\u00ec chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00e0 3,35s. Khi thang m\u00e1y \u0111\u1ee9ng y\u00ean th\u00ec chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00e0: A. 2,84s B. 1,99s C. 2,56s D. 3,98s KI\u1ec2U 2: NGO\u1ea0I L\u1ef0C C\u00d3 PH\u01af\u01a0NG NGANG C\u00e2u 88: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m v\u1eadt n\u1eb7ng kh\u1ed1i l\u01b0\u1ee3ng m=10g v\u00e0 d\u00e2y treo c\u00f3 chi\u1ec1u d\u00e0i l = 1 m. T\u00edch \u0111i\u1ec7n cho v\u1eadt n\u1eb7ng q = 10\u22126 C. K\u00edch th\u00edch cho con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=10 m\/s2 v\u00e0 \u0111i\u1ec7n tr\u01b0\u1eddng E = 105 V\/m theo ph\u01b0\u01a1ng ngang. Chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. 1,67 s. B. 2,41 s. C. 4,22 s. D. 1,03 s. TRANG 83","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 89: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m s\u1ee3i d\u00e2y nh\u1eb9 d\u00e0i l = 25 cm, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=10g v\u00e0 mang \u0111i\u1ec7n t\u00edch q = 4.10\u22124 C. Treo con l\u1eafc gi\u1eefa hai b\u1ea3n kim lo\u1ea1i ph\u1eb3ng, th\u1eb3ng \u0111\u1ee9ng, song song c\u00e1ch nhau 22 cm. \u0110\u1eb7t gi\u1eefa hai b\u1ea3n m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf kh\u00f4ng \u0111\u1ed5i U = 88 V. L\u1ea5y g = 10 m\/s2. K\u00edch th\u00edch cho con l\u1eafc dao \u0111\u1ed9ng v\u1edbi bi\u00ean \u0111\u1ed9 nh\u1ecf, chu k\u00ec dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u1ee7a con l\u1eafc l\u00e0 A. 0,389 s. B. 0,659 s. C. 0,983 s. D. 0,723 s. C\u00e2u 90: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m qu\u1ea3 c\u1ea7u kim lo\u1ea1i nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m = 1g mang \u0111i\u1ec7n t\u00edch q = \u22125,66.10\u22127 C \u0111\u01b0\u1ee3c treo b\u1eb1ng s\u1ee3i d\u00e2y m\u1ea3nh d\u00e0i l = 1, 4 m trong ch\u00e2n kh\u00f4ng v\u00e0 trong \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u c\u00f3 ph\u01b0\u01a1ng n\u1eb1m ngang, c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 E = 100 V\/m. L\u1ea5y g = 9,79 m\/s2. \u1ede v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng d\u00e2y treo t\u1ea1o v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng m\u1ed9t g\u00f3c \uf061 . G\u00f3c \uf061 v\u00e0 chu k\u00ec dao \u0111\u1ed9ng T c\u1ee7a con l\u1eafc \u0111\u01a1n l\u00e0 A. \uf061 = 0,330 , T = 2,37 s. B. \uf061 = 300 , T = 2, 21 s. C. \uf061 = 200 , T = 2, 21 s. D. \uf061 = 300 , T = 2,37 s. C\u00e2u 91: M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m d\u00e2y treo c\u00f3 chi\u1ec1u d\u00e0i 1m v\u00e0 v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g mang \u0111i\u1ec7n t\u00edch 2.10-5C. Treo con l\u1eafc \u0111\u01a1n n\u00e0y v\u00e0o trong m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng h\u01b0\u1edbng theo ph\u01b0\u01a1ng ngang v\u1edbi \u0111\u1ed9 l\u1edbn E=5.104V\/m. Trong m\u1eb7t ph\u1eb3ng th\u1eb3ng \u0111\u1ee9ng \u0111i qua \u0111i\u1ec3m treo v\u00e0 song song v\u1edbi v\u00e9c t\u01a1 c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng, k\u00e9o v\u1eadt nh\u1ecf theo chi\u1ec1u c\u1ee7a v\u00e9c t\u01a1 c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng sao cho d\u00e2y treo h\u1ee3p v\u1edbi v\u00e9c t\u01a1 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 1 g\u00f3c 54o r\u1ed3i th\u1ea3 nh\u1eb9 cho con l\u1eafc dao \u0111\u1ed9ng. L\u1ea5y g=10m\/s2. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, t\u1ed1c \u0111\u1ed9 c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt l\u00e0: A. 0,59m\/s B. 3,14m\/s C. 2,87m\/s D. 0,5m\/s C\u00e2u 92: M\u1ed9t CL\u0110 c\u00f3 chi\u1ec1u d\u00e0i l=0,5m; c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g. CL\u0110 ch\u1ecbu th\u00eam t\u00e1c d\u1ee5ng c\u1ee7a ngo\u1ea1i l\u1ef1c c\u00f3 \u0111\u1ed9 l\u1edbn 1N theo ph\u01b0\u01a1ng ngang h\u01b0\u1edbng t\u1eeb tr\u00e1i sang ph\u1ea3i. K\u00e9o con l\u1eafc \u0111\u01a1n l\u1ec7ch kh\u1ecfi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng 1 g\u00f3c 540 r\u1ed3i th\u1ea3 nh\u1eb9 T\u00ednh v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt khi s\u1ee3i d\u00e2y l\u1ec7ch sang ph\u1ea3i so v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng g\u00f3c 40o, l\u1ea5y g=10m\/s2 A. 0,35 m\/s B. 0,4 m\/s C. 0,45m\/s D. 0,5 m\/s KI\u1ec2U 3: NGO\u1ea0I L\u1ef0C C\u00d3 PH\u01af\u01a0NG B\u1ea4T K\u00cc C\u00e2u 93: (VDC-THPT Tri\u1ec7u S\u01a1n \u2013 2016) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l = 1 m, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m = 100 3 g, t\u00edch \u0111i\u1ec7n q = 10\u22125 C. Treo con l\u1eafc \u0111\u01a1n trong m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u c\u00f3 ph\u01b0\u01a1ng vu\u00f4ng g\u00f3c v\u1edbi vecto g v\u00e0 \u0111\u1ed9 l\u1edbn E = 105 V\/m. K\u00e9o v\u1eadt theo chi\u1ec1u c\u1ee7a vecto c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng sao cho g\u00f3c t\u1ea1o b\u1edfi gi\u1eefa d\u00e2y treo v\u00e0 vecto g l\u00e0 750 th\u1ea3 nh\u1eb9 \u0111\u1ec3 v\u1eadt chuy\u1ec3n \u0111\u1ed9ng. L\u1ea5y g = 10 m\/s2. L\u1ef1c c\u0103ng c\u1ef1c \u0111\u1ea1i c\u1ee7a d\u00e2y treo l\u00e0: A. 3,17 N. B. 2,14 N. C. 1,54 N. D. 5,54 N. C\u00e2u 94: (VDC-Chuy\u00ean H\u00e0 T\u0129nh-2018) M\u1ed9t con l\u1eafc \u0111\u01a1n g\u1ed3m v\u1eadt nh\u1ecf kh\u1ed1i l\u01b0\u1ee3ng m mang \u0111i\u1ec7n t\u00edch d\u01b0\u01a1ng q v\u00e0 s\u1ee3i d\u00e2y nh\u1eb9, kh\u00f4ng d\u00e3n d\u00e0i l \u0111\u01b0\u1ee3c \u0111\u1eb7t t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g. B\u1ecf qua s\u1ee9c c\u1ea3n c\u1ee7a kh\u00f4ng kh\u00ed. Cho con l\u1eafc dao \u0111\u1ed9ng nh\u1ecf th\u00ec chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0 2 s. Khi duy tr\u00ec m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 E v\u00e0 h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng xu\u1ed1ng d\u01b0\u1edbi th\u00ec con l\u1eafc dao \u0111\u1ed9ng \u2192\u2192 nh\u1ecf v\u1edbi chu k\u00ec 1s. N\u1ebfu gi\u1eef nguy\u00ean c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng nh\u01b0ng E c\u00f3 h\u01b0\u1edbng h\u1ee3p v\u1edbi g g\u00f3c 600 th\u00ec chu k\u00ec dao \u0111\u1ed9ng nh\u1ecf c\u1ee7a con l\u1eafc l\u00e0: A. 1,075s B. 0,816s C. 1,732s D. 0,577s TRANG 84","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 95: (VDC- \u0110H-2019) Hai con l\u1eafc \u0111\u01a1n gi\u1ed1ng h\u1ec7t nhau m\u00e0 c\u00e1c v\u1eadt nh\u1ecf mang \u0111i\u1ec7n t\u00edch nh\u01b0 nhau, \u0111\u01b0\u1ee3c treo \u1edf c\u00f9ng m\u1ed9t n\u01a1i tr\u00ean m\u1eb7t \u0111\u1ea5t. Trong m\u1ed7i v\u00f9ng kh\u00f4ng gian ch\u1ee9a m\u1ed7i con l\u1eafc c\u00f3 m\u1ed9t \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u. Hai \u0111i\u1ec7n tr\u01b0\u1eddng n\u00e0y c\u00f3 c\u00f9ng c\u01b0\u1eddng \u0111\u1ed9 nh\u01b0ng c\u00e1c \u0111\u01b0\u1eddng s\u1ee9c vu\u00f4ng g\u00f3c v\u1edbi nhau. Gi\u1eef hai con l\u1eafc \u1edf v\u1ecb tr\u00ed c\u00e1c d\u00e2y treo c\u00f3 ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng r\u1ed3i th\u1ea3 nh\u1eb9 th\u00ec ch\u00fang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a trong c\u00f9ng m\u1ed9t m\u1eb7t ph\u1eb3ng v\u1edbi c\u00f9ng bi\u00ean \u0111\u1ed9 g\u00f3c 8\u00b0 v\u00e0 chu k\u1ef3 t\u01b0\u01a1ng \u1ee9ng l\u00e0 T1 v\u00e0 T2 = T1 + 0,25s. Gi\u00e1 tr\u1ecb c\u1ee7a T1 l\u00e0 A. 1,895s B. 1,645s C. 1,974s D. 2,274s C\u00e2u 96: (VDC-Minh H\u1ecda-2020) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 v\u1eadt nh\u1ecf mang \u0111i\u1ec7n t\u00edch d\u01b0\u01a1ng \u0111\u01b0\u1ee3c treo \u1edf m\u1ed9t n\u01a1i tr\u00ean m\u1eb7t \u0111\u1ea5t trong \u0111i\u1ec7n tr\u01b0\u1eddng \u0111\u1ec1u c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng E . Khi E h\u01b0\u1edbng th\u1eb3ng \u0111\u1ee9ng xu\u1ed1ng d\u01b0\u1edbi th\u00ec con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T1 . Khi E c\u00f3 ph\u01b0\u01a1ng n\u1eb1m ngang th\u00ec con l\u1eafc \u0111\u01a1n dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T2 . Bi\u1ebft trong hai tr\u01b0\u1eddng h\u1ee3p, \u0111\u1ed9 l\u1edbn c\u01b0\u1eddng \u0111\u1ed9 \u0111i\u1ec7n tr\u01b0\u1eddng b\u1eb1ng nhau. T\u1ec9 s\u1ed1 T2 c\u00f3 th\u1ec3 nh\u1eadn gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y? T1 A. 0,89 B. 1,23 C. 0,96 D. 1,15 D\u1ea0NG 6 (N\u00c2NG CAO): CON L\u1eaeC \u0110\u01a0N B\u1eca V\u01af\u1edaNG \u0110INH PH\u01af\u01a0NG PH\u00c1P \u2756 M\u1ed9t con l\u1eafc \u0111\u01a1n \u0111ang dao \u0111\u1ed9ng v\u1edbi chi\u1ec1u d\u00e0i l1 th\u00ec khi \u0111i qua VTCB n\u00f3 b\u1ecb v\u01b0\u1edbng v\u00e0o \u0111inh t\u1ea1i O\u2019 l\u00e0m cho con l\u1eafc dao \u0111\u1ed9ng v\u1edbi chi\u1ec1u d\u00e0i l2 n\u00ean chu k\u00ec, bi\u00ean \u0111\u1ed9 g\u00f3c\u2026c\u0169ng thay \u0111\u1ed5i theo. \u2756 Chu k\u00ec c\u1ee7a con l\u1eafc v\u01b0\u1edbng \u0111inh ( )T=1 + = \uf070. 2 .(T1 T2 ) g 1+ 2 \u2756 N\u1ebfu Fc=0 th\u00ec WB=WA \u2756 N\u1ebfu \u03b1o > 100 th\u00ec: 1 = 1\u2212 cos \uf06102 2 1\u2212 cos \uf06101 \u2756 N\u1ebfu \u03b1o < 100 th\u00ec: 2 = \uf06101 1 \uf06102 C\u00e2u 97: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l=1m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec T t\u1ea1i n\u01a1i c\u00f3 gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=\u03c02=10 m\/s2. Nh\u01b0ng khi \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng d\u00e2y treo b\u1ecb v\u01b0\u1edbng \u0111inh t\u1ea1i v\u1ecb tr\u00ed 0,5l v\u00e0 con l\u1eafc ti\u1ebfp t\u1ee5c dao \u0111\u1ed9ng. T\u00ednh chu k\u00ec c\u1ee7a con l\u1eafc \u0111\u01a1n n\u00e0y: A. 2s B. 2 s C. 2+ 2 s D. 2 + 2 s 2 C\u00e2u 98: K\u00e9o con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i l=1m ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t g\u00f3c nh\u1ecf so v\u1edbi ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng r\u1ed3i th\u1ea3 nh\u1eb9 cho n\u00f3 dao \u0111\u1ed9ng. Khi \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, d\u00e2y treo b\u1ecb v\u01b0\u1edbng v\u00e0o m\u1ed9t chi\u1ebfc \u0111inh \u0111\u00f3ng d\u01b0\u1edbi \u0111i\u1ec3m treo con l\u1eafc m\u1ed9t \u0111o\u1ea1n 36cm. L\u1ea5y g=\u03c02=10m\/s2. T\u00ednh chu k\u00ec dao \u0111\u1ed9ng: A. 3,6s B. 2,2s C. 1,99s D. 1,8s TRANG 85","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 99: M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1m treo v\u00e0o m\u1ed9t \u0111i\u1ec3m c\u1ed1 \u0111\u1ecbnh. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng O, k\u00e9o v\u1eadt v\u1ec1 b\u00ean ph\u1ea3i \u0111\u1ebfn A r\u1ed3i th\u1ea3 nh\u1eb9. M\u1ed7i khi v\u1eadt nh\u1ecf \u0111i t\u1eeb ph\u1ea3i sang tr\u00e1i ngang qua O th\u00ec d\u00e2y v\u01b0\u1edbng v\u00e0o \u0111inh nh\u1ecf t\u1ea1i C, v\u1eadt dao \u0111\u1ed9ng tr\u00ean qu\u1ef9 \u0111\u1ea1o AOB nh\u01b0 h\u00ecnh v\u1ebd. Bi\u1ebft \u03b11=60 v\u00e0 \u03b12=90. B\u1ecf qua m\u1ecdi ma s\u00e1t. L\u1ea5y g=\u03c02. Chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. 5 s B. 5 s C. 5 s D. 5 s 6 3 4 2 C\u00e2u 100: (Minh H\u1ecda-2017) M\u1ed9t con l\u1eafc \u0111\u01a1n \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c 50. Khi v\u1eadt n\u1eb7ng \u0111i qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng th\u00ec ng\u01b0\u1eddi ta gi\u1eef ch\u1eb7t \u0111i\u1ec3m ch\u00ednh gi\u1eefa c\u1ee7a d\u00e2y treo, sau \u0111\u00f3 v\u1eadt ti\u1ebfp t\u1ee5c dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c \u03b1 b\u1eb1ng: A. 7,10 B. 100 C. 3,50 D. 2,50 C\u00e2u 101: (VDC-\u0110H-2017) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 1,92m treo v\u00e0o \u0111i\u1ec3m T c\u1ed1 \u0111\u1ecbnh. T\u1eeb v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng O, k\u00e9o con l\u1eafc v\u1ec1 b\u00ean ph\u1ea3i \u0111\u1ebfn A r\u1ed3i th\u1ea3 nh\u1eb9. M\u1ed7i khi v\u1eadt nh\u1ecf \u0111i t\u1eeb ph\u1ea3i sang tr\u00e1i ngang qua B th\u00ec d\u00e2y treo v\u01b0\u1edbng v\u00e0o \u0111inh nh\u1ecf t\u1ea1i D, v\u1eadt dao \u0111\u1ed9ng tr\u00ean qu\u1ef9 \u0111\u1ea1o AOBC nh\u01b0 h\u00ecnh v\u1ebd. Bi\u1ebft TD=1,28m v\u00e0 \u03b11=\u03b12=40. B\u1ecf qua m\u1ecdi ma s\u00e1t. L\u1ea5y g=\u03c02. Chu k\u00ec dao \u0111\u1ed9ng c\u1ee7a con l\u1eafc l\u00e0: A. 2,26s B. 2,61s C. 1,6s D. 2,77s B\u1ea2NG \u0110\u00c1P \u00c1N 1.C 2.D 3.C 4.C 5.A 6.C 7.D 8.B 9.D 10.D 11.C 12.A 13.B 14.B 15.C 16.A 17.C 18.A 19.A 20.C 21.B 22.C 23.A 24.C 25.A 26.B 27.D 28.D 29.D 30.C 31.D 32.C 33.B 34.A 35.B 36.C 37.B 38.B 39.D 40.B 41.D 42.C 43.C 44.D 45.D 46.D 47.C 48.D 49.B 50.B 51.C 52.B 53.D 54.C 55.B 56.C 57.A 58.A 59.D 60.A 61.C 62.B 63.C 64.C 65.A 66.C 67.B 68.B 69.A 70.D 71.C 72.A 73.B 74.B 75.A 76.D 77.A 78.C 79.D 80.D 81.C 82.A 83.A 84.A 85.C 86.A 87.C 88.A 89.D 90.B 91.A 92.A 93.A 94.A 95.B 96.D 101.D 102.D 103.B 104.A 105.B QR CODE PDF L\u1eddi gi\u1ea3i TRANG 86","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 CH\u1ee6 \u0110\u1ec0 4: T\u1ed4NG H\u1ee2P DAO \u0110\u1ed8NG & C\u00c1C LO\u1ea0I DAO \u0110\u1ed8NG CH\u1ee6 \u0110\u1ec0 4: T\u1ed4NG H\u1ee2P DAO \u0110\u1ed8NG & C\u00c1C LO\u1ea0I DAO \u0110\u1ed8NG D\u1ea0NG 1: T\u1ed4NG H\u1ee2P DAO \u0110\u1ed8NG C\u01a0 B\u1ea2N PH\u01af\u01a0NG PH\u00c1P \u2756M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai dao \u0111\u1ed9ng: \uf0ec\uf0ed\uf0eexx12 = A1cos (wt + \uf06a1) = A2cos (wt + \uf06a2 ) \u2756 Ph\u01b0\u01a1ng tr\u00ecnh t\u1ed5ng h\u1ee3p dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0: x = x1 + x2 = Acos(wt + \uf06a) \u2756 C\u00e1ch 1: T\u00ednh A v\u00e0 \uf06a theo c\u00f4ng th\u1ee9c \u0111\u1ea1i s\u1ed1 A= A12 + A 2 + 2A1A2 cos(\uf06a2 \u2212 \uf06a1) & tan \uf06a = A1 sin \uf06a1 + A2 sin \uf06a2 2 A1 cos \uf06a1 + A2 cos \uf06a2 \u2756 C\u00e1ch 2: T\u00ednh t\u1ed5ng h\u1ee3p dao \u0111\u1ed9ng b\u1eb1ng ph\u01b0\u01a1ng ph\u00e1p CASIO VINACAL ho\u1eb7c CASIO 570 VN CASIO 580VNX B1 \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb ch\u1eef R \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb ch\u1eef R B2 \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb k\u00ed hi\u1ec7u ch\u1eef: i \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb ch\u1eef CMPLX B3 \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb: A1 \uf0d0 (\u03c61) + A2 \uf0d0 (\u03c62) \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb: A1 \uf0d0 (\u03c61) + A2 \uf0d0 (\u03c62) B4 \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb:A \uf0d0 (\u03c6) \u27a2M\u00e0n h\u00ecnh s\u1ebd hi\u1ec7n th\u1ecb: A \uf0d0 (\u03c6) \u2756Ch\u00fa \u00fd: Khi th\u1ef1c hi\u1ec7n b\u1ea5m m\u00e1y t\u00ednh th\u00ec c\u00e1c ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng ph\u1ea3i chuy\u1ec3n v\u1ec1 chung m\u1ed9t d\u1ea1ng h\u00e0m ( cos ho\u1eb7c sin) C\u00e2u 1: (\u0110H-2021) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1, ng\u01b0\u1ee3c pha nhau, c\u00f3 bi\u00ean \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1 v\u00e0 A2. Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng n\u00e0y c\u00f3 bi\u00ean \u0111\u1ed9 l\u00e0 A. C\u00f4ng th\u1ee9c n\u00e0o sau \u0111\u00e2y \u0111\u00fang? A. A = A1 + A2 B. A = 1. A1 \u2212 A2 C. A = A1 \u2212 A2 D. A = 1 + A2) 2 2 (A1 C\u00e2u 2: (\u0110H-2021) Hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 bi\u00ean \u0111\u1ed9 v\u00e0 pha ban \u0111\u1ea7u l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1, \uf06a1 v\u00e0 A2, \uf06a1 . Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng n\u00e0y c\u00f3 pha ban \u0111\u1ea7u l\u00e0 \uf0661 \u0111\u01b0\u1ee3c t\u00ednh theo c\u00f4ng th\u1ee9c: A. tan \uf06a = A1 sin \uf06a1 \u2212 A2 sin \uf06a2 B. tan \uf06a = A1 sin \uf06a1 + A2 sin \uf06a2 A1 cos \uf06a1 + A2 cos \uf06a2 A1 cos \uf06a1 + A2 cos \uf06a2 C. tan \uf06a = A1 cos \uf06a1 \u2212 A2 cos \uf06a2 D. tan \uf06a = A1 sin \uf06a1 + A2 sin \uf06a2 A1 sin \uf06a1 + A2 sin \uf06a2 A1 cos \uf06a1 \u2212 A2 cos \uf06a2 TRANG 87","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 3: (\u0110H-2020) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 v\u00e0 c\u00f3 \u0111\u1ed9 l\u1ec7ch pha \u2206\u03c6. N\u1ebfu hai C\u00e2u 4: dao \u0111\u1ed9ng c\u00f9ng pha th\u00ec c\u00f4ng th\u1ee9c n\u00e0o sau \u0111\u00e2y l\u00e0 \u0111\u00fang? A. \u2206\u03c6 = (2n + 1) v\u1edbi n = 0; \u00b1 1; \u00b1 2;\u2026. B. \u2206\u03c6 = 2n\u03c0 v\u1edbi n = 0; \u00b1 1; \u00b1 2;\u2026. C. \u2206\u03c6 = \uf0e6 2n + 1\uf0f6 v\u1edbi n = 0; \u00b1 1; \u00b1 2;\u2026. D. \u2206\u03c6 = \uf0e6 2n + 1\uf0f6 v\u1edbi n = 0; \u00b1 1; \u00b1 2;\u2026. \uf0e7\uf0e8 2 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 (\u0110H-2020) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1, ng\u01b0\u1ee3c pha nhau, c\u00f3 bi\u00ean \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1 v\u00e0 A2. Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng n\u00e0y c\u00f3 bi\u00ean \u0111\u1ed9 l\u00e0 A. C\u00f4ng th\u1ee9c n\u00e0o sau \u0111\u00e2y \u0111\u00fang? A. A = A1 + A2 B. A = A1 \u2212 A2 C. A = A1 \u2212 A2 D. A = A1 + A2 C\u00e2u 5: (\u0110H-2020) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1, c\u00f9ng pha nhau, c\u00f3 bi\u00ean \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1 v\u00e0 A2. Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng n\u00e0y c\u00f3 bi\u00ean \u0111\u1ed9 l\u00e0 A. C\u00f4ng th\u1ee9c n\u00e0o sau \u0111\u00e2y \u0111\u00fang? A. A = A1 + A2 B. A = A1 \u2212 A2 C. A = A1 \u2212 A2 D. A = A1 + A2 C\u00e2u 6: (\u0110H-2018) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1. Hai dao \u0111\u1ed9ng n\u00e0y ng\u01b0\u1ee3c pha nhau khi \u0111\u1ed9 l\u1ec7ch pha c\u1ee7a hai dao \u0111\u1ed9ng b\u1eb1ng: A. (2n+1) \u03c0 v\u1edbi n = 0, \u00b11, \u00b12\u2026. B. 2n\u03c0 v\u1edbi n= 0, \u00b1 1, \u00b12\u2026 C. (2n+1) \u03c0\/2 v\u1edbi n=0, \u00b1 1, \u00b12\u2026 D. (2n+1). \u03c0\/4 v\u1edbi n=0, \u00b11, \u00b1 2\u2026 C\u00e2u 7: (\u0110H-2018) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng n\u00e0y c\u00f3 gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t khi \u0111\u1ed9 l\u1ec7ch pha c\u1ee7a hai dao \u0111\u1ed9ng b\u1eb1ng: A. (2n+1). \u03c0\/4 v\u1edbi n=0, \u00b11, \u00b1 2\u2026 B. (2n+1) \u03c0\/2 v\u1edbi n=0, \u00b1 1, \u00b12\u2026 C. (2n+1) \u03c0 v\u1edbi n = 0, \u00b11, \u00b12\u2026. D. 2n\u03c0 v\u1edbi n= 0, \u00b1 1, \u00b12\u2026 C\u00e2u 8: M\u1ed9t v\u1eadt \u0111\u1ed3ng th\u1eddi th\u1ef1c hi\u1ec7n hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0: x1 = 3cos \uf0e6 2\uf070t + \uf070 \uf0f6 (cm) v\u00e0 x2 = 1cos \uf0e6 2\uf070t + 2\uf070 \uf0f6 (cm). Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0: \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 A. x = 2cos \uf0e6 2\uf070t + \uf070 \uf0f6 cm B. x = 3cos \uf0e6 2\uf070t + \uf070 \uf0f6 cm \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 6 \uf0f7\uf0f8 C. x = 2cos \uf0e6 2\uf070t + \uf070 \uf0f6 cm D. x = cos\uf0e6\uf0e7\uf0e8 2\uf070t + \uf070 \uf0f6 cm \uf0e7\uf0e8 3 \uf0f7\uf0f8 6 \uf0f7\uf0f8 C\u00e2u 9: Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 x = 3cos\uf0e6\uf0e7\uf0e8 \uf070t \u2212 5\uf070 \uf0f6 cm. Bi\u1ebft dao \u0111\u1ed9ng th\u1ee9 nh\u1ea5t c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 x1 = 5cos\uf0e6\uf0e7\uf0e8 \uf070t + \uf070 \uf0f6 (cm). 6 \uf0f7\uf0f8 6 \uf0f7\uf0f8 Dao \u0111\u1ed9ng th\u1ee9 hai c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 l\u00e0: A. x2 = 8cos\uf0e6\uf0e7\uf0e8 \uf070t + \uf070\uf0f6 (cm) B. x2 = 2cos \uf0e6 \uf070t + \uf070 \uf0f6 (cm) 6 \uf0f7\uf0f8 \uf0e7\uf0e8 6 \uf0f7\uf0f8 C. x2 = 2cos \uf0e6 \uf070t \u2212 5\uf070 \uf0f6 (cm) D. x2 = 8cos \uf0e6 \uf070t \u2212 5\uf070 \uf0f6 (cm) \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 6 \uf0f7\uf0f8 C\u00e2u 10: Chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a m\u1ed9t v\u1eadt l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng x1 = 3cos\uf0e6\uf0e7\uf0e830t + \uf070 \uf0f6 cm v\u00e0 x2 = 4cos\uf0e6\uf0e7\uf0e830t + 3\uf070 \uf0f6 cm. T\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt khi qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 4 \uf0f8\uf0f7 4 \uf0f7\uf0f8 A. 1.5m\/s B. 0,3m\/s C. 0,3cm\/s D. 1,5cm\/s TRANG 88","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 11: M\u1ed9t v\u1eadt \u0111\u1ed3ng th\u1eddi ba dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1, bi\u1ec3u th\u1ee9c c\u00f3 d\u1ea1ng x1 = 2 3cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 cm; x2 = 4cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 cm; x3 = 8cos(2\uf070t \u2212 \uf070) cm. Ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p A. x = 6cos\uf0e6\uf0e7\uf0e8 2\uf070t \u2212 \uf070\uf0f6 cm B. x = 6sin \uf0e6 2\uf070t \u2212 \uf070\uf0f6 cm 4 \uf0f7\uf0f8 \uf0e7\uf0e8 6 \uf0f7\uf0f8 C. x = 6cos \uf0e6 2\uf070t \u2212 2\uf070 \uf0f6 cm D. x = 6sin \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 cm \uf0e7\uf0e8 3 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 C\u00e2u 12: Dao \u0111\u1ed9ng c\u1ee7a v\u1eadt ch\u1ea5t \u0111i\u1ec3m c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 200g l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 5cos10t v\u00e0 x2 = 10cos10t (cm). C\u01a1 n\u0103ng c\u1ee7a ch\u1ea5t \u0111i\u1ec3m A. 0,225J B. 225J C. 112,5J D. 0,1125J C\u00e2u 13: Trong con l\u1eafc l\u00f2 xo, v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=200g \u0111\u1ed3ng th\u1eddi th\u1ef1c hi\u1ec7n hai \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x = 6cos \uf0e6\uf0e7\uf0e8 5\uf070t \u2013 \uf070 \uf0f6 (cm) v\u00e0 x2 = 6cos5\uf070t (cm). L\u1ea5y \u03c02=10. Th\u1ebf n\u0103ng 1 2 \uf0f8\uf0f7 c\u1ee7a v\u1eadt t\u1ea1i th\u1eddi \u0111i\u1ec3m t=1s l\u00e0: A. 90mJ B. 180mJ C. 900mJ D. 180mJ C\u00e2u 14: M\u1ed9t v\u1eadt tham gia \u0111\u1ed3ng th\u1eddi hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = 2cos \uf0e6 2\uf070t + \uf070 \uf0f6 (cm) v\u00e0 x2 = 2sin \uf0e6 2\uf070t \u2013 \uf070\uf0f6 (cm). T\u00ednh qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt \u0111i \u0111\u01b0\u1ee3c t\u1eeb th\u1eddi \uf0e7\uf0e8 2 \uf0f8\uf0f7 \uf0e7\uf0e8 2 \uf0f7\uf0f8 \u0111i\u1ec3m t=4,25s \u0111\u1ebfn t=4,375s: A. 10cm B. 9cm C. 6cm D. 2cm C\u00e2u 15: V\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai \u0111\u1ed9ng c\u00f9ng ph\u01b0\u01a1ng c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = 8cos \uf0e6 20t \u2212 \uf070\uf0f6 cm v\u00e0 \uf0e7\uf0e8 3 \uf0f7\uf0f8 x2 = 3cos\uf0e6\uf0e7\uf0e8 20t + \uf070 \uf0f6 cm. T\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt khi n\u00f3 \u1edf v\u1ecb tr\u00ed c\u00e1ch v\u1ecb tr\u00ed th\u1ebf n\u0103ng c\u1ef1c \u0111\u1ea1i g\u1ea7n nh\u1ea5t 4cm 3 \uf0f7\uf0f8 A. 20 33 cm\/s B. 5 3 cm\/s C. 140cm\/s D. 40 10 cm\/s C\u00e2u 16: Con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf n\u1eb7ng 1kg th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng, theo c\u00e1c ph\u01b0\u01a1ng tr\u00ecnh x1 = 5 2cos10t (cm) v\u00e0 x2 = 5 2sin10t (cm), g=10m\/s2. L\u1ef1c c\u1ef1c \u0111\u1ea1i m\u00e0 l\u00f2 xo t\u00e1c d\u1ee5ng l\u00ean v\u1eadt l\u00e0: A. 10N B. 20N C. 25N D. 0,25N C\u00e2u 17: M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 1 (kg) tham gia \u0111\u1ed3ng th\u1eddi 2 dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1 g\u00f3c 10 (rad\/s). Bi\u00ean \u0111\u1ed9 c\u1ee7a 2 dao \u0111\u1ed9ng l\u00e0 A1 = A2 = 3 cm. Pha ban \u0111\u1ea7u c\u1ee7a 2 dao \u0111\u1ed9ng l\u00e0 \u03c0\/6 v\u00e0 5\u03c0\/6. C\u01a1 n\u0103ng dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. 0,03 J B. 0,015 J. C. 150 J. D. 0,02 J. C\u00e2u 18: M\u1ed9t ch\u1ea5t \u0111i\u1ec3m th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a, c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x1 = 5cos \uf0e6 wt + 5\uf070 \uf0f6 v\u00e0 x2 = 10sinwt . Pha ban \u0111\u1ea7u c\u1ee7a dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p: \uf0e7\uf0e8 6 \uf0f7\uf0f8 A. \u03c0\/3 B. -2\u03c0\/3 C. -5\u03c0\/6 D. \u03c0\/6 TRANG 89","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 19: M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 d\u1ea1ng x1 = 4cos\uf0e6\uf0e7\uf0e810t \u2013 \uf070\uf0f6 cm v\u00e0 x2 = A2cos(10t + \uf070) cm. Bi\u1ebft r\u1eb1ng v\u1eadn t\u1ed1c c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt trong qu\u00e1 3 \uf0f7\uf0f8 tr\u00ecnh dao \u0111\u1ed9ng b\u1eb1ng 0,2 7 m\/s. X\u00e1c \u0111\u1ecbnh gi\u00e1 tr\u1ecb c\u1ee7a A2 A. 4cm B. 5cm C. 6cm D. 3cm C\u00e2u 20: Hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = 6cos\uf0e7\uf0e6\uf0e810t + \uf070 \uf0f6 (cm) v\u00e0 6 \uf0f7\uf0f8 x2 = 6cos \uf0e6\uf0e7\uf0e810t + 5\uf070 \uf0f6 (cm). T\u1ea1i th\u1eddi \u0111i\u1ec3m li \u0111\u1ed9 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0 3m v\u00e0 \u0111ang gi\u1ea3m th\u00ec li \u0111\u1ed9 6 \uf0f8\uf0f7 c\u1ee7a dao \u0111\u1ed9ng th\u1ee9 hai l\u00e0 bao nhi\u00eau? A. 10 cm. B. 9 cm. C. 6cm. D. \u22123cm. C\u00e2u 21: Hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = 6cos \uf0e6\uf0e7\uf0e810t + \uf070 \uf0f6 (cm) v\u00e0 3 \uf0f7\uf0f8 x2 = 8cos\uf0e6\uf0e7\uf0e810t \u2212 \uf070\uf0f6 (cm). T\u1ea1i th\u1eddi \u0111i\u1ec3m li \u0111\u1ed9 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0 8 cm v\u00e0 \u0111ang gi\u1ea3m th\u00ec li \u0111\u1ed9 6 \uf0f7\uf0f8 c\u1ee7a dao \u0111\u1ed9ng th\u1ee9 hai l\u00e0 bao nhi\u00eau? A. 10 cm. B. 9 cm. C. 8cm. D. 11cm. C\u00e2u 22: Hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = 6cos \uf0e6\uf0e7\uf0e810t + \uf070 \uf0f6 (cm) v\u00e0 3 \uf0f7\uf0f8 x2 = 8cos\uf0e6\uf0e7\uf0e810t \u2212 \uf070\uf0f6 (cm). T\u1ea1i th\u1eddi \u0111i\u1ec3m li \u0111\u1ed9 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0 5 cm v\u00e0 \u0111ang gi\u1ea3m th\u00ec li \u0111\u1ed9 6 \uf0f7\uf0f8 c\u1ee7a dao \u0111\u1ed9ng th\u1ee9 hai l\u00e0 bao nhi\u00eau? A. 7,36 cm. B. 9 cm. C. 8 cm. D. 11cm. C\u00e2u 23: Dao \u0111\u1ed9ng c\u1ee7a ch\u1ea5t \u0111i\u1ec3m l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 3cos \uf0e6 2\uf070 t \u2212 \uf070\uf0f6 v\u00e0 x2 = 3 3 cos \uf0e6\uf0e7\uf0e8 2\uf070 t \uf0f6 (x1 v\u00e0 x2 t\u00ednh b\u1eb1ng cm, t t\u00ednh b\u1eb1ng s). \uf0e7\uf0e8 3 2 \uf0f7\uf0f8 3 \uf0f7\uf0f8 T\u1ea1i c\u00e1c th\u1eddi \u0111i\u1ec3m x1 = x2 li \u0111\u1ed9 dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0 A. 5,79 cm. B. 5,19 cm. C. 6 cm. D. 3 cm. C\u00e2u 24: M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi 3 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng pha c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = A1cos \uf0e6 2\uf070t + 2\uf070 \uf0f6 (cm), x2 = A2cos(2\uf070t ) (cm), x3 = A3cos \uf0e6 2\uf070t \u2013 2\uf070 \uf0f6 (cm). T\u1ea1i th\u1eddi \uf0e7\uf0e8 3 \uf0f8\uf0f7 \uf0e7\uf0e8 3 \uf0f8\uf0f7 \u0111i\u1ec3m t1 c\u00e1c gi\u00e1 tr\u1ecb li \u0111\u1ed9 x1(t1) = \u221210 cm, x2 (t1) = 40 cm, x3 (t1)= \u221220 cm. Th\u1eddi \u0111i\u1ec3m t2 = t1 + T\/4 c\u00e1c gi\u00e1 tr\u1ecb li \u0111\u1ed9 x1(t2) = \u221210 3 cm, x2 (t2)= 0 cm, x3(t2) = 20 3 cm. T\u00ecm ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p? A. x = 30cos \uf0e6 2\uf070t + \uf070 \uf0f6 (cm). B. x = 20cos \uf0e6 2\uf070t \u2212 \uf070\uf0f6 (cm). \uf0e7\uf0e8 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f8\uf0f7 C. x = 40cos \uf0e6 2\uf070t + \uf070 \uf0f6 (cm). D. x = 20 2 cos \uf0e6 2\uf070t \u2212 \uf070 \uf0f6 (cm). \uf0e7\uf0e8 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 TRANG 90","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 25: M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi ba dao \u0111\u1ed9ng \u0111i\u1ec1u ho\u00e0 c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0: x1 = A1cos \uf0e6 2\uf070t + 2\uf070 \uf0f6 cm; x2 = A2cos(2\uf070t) cm; x3 = A3cos \uf0e6 2\uf070t \u2212 2\uf070 \uf0f6 cm. T\u1ea1i th\u1eddi \uf0e7\uf0e8 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 \uf0f7\uf0f8 \u0111i\u1ec3m t1 (s) c\u00f3 gi\u00e1 tr\u1ecb li \u0111\u1ed9 l\u00e0 x1 = -20 cm; x2=80 cm; x3=-40 cm. T\u1ea1i th\u1eddi \u0111i\u1ec3m t2=t1+0,25 (s) c\u00e1c gi\u00e1 tr\u1ecb li \u0111\u1ed9 x1=-20 3 cm; x2= 0 cm; x3= 40 3 cm. Bi\u00ean \u0111\u1ed9 c\u1ee7a dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0: A. 50 cm B. 40 cm C. 20 2 cm D. 30 cm. C\u00e2u 26: M\u1ed9t con l\u1eafc l\u00f2 xo tham gia \u0111\u1ed3ng th\u1eddi hai dao \u0111\u1ed9ng c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 g\u00f3c 5 2 (rad\/s) c\u00f3 \u0111\u1ed9 l\u1ec7ch pha b\u1eb1ng 2\u03c0\/3 v\u00e0 bi\u00ean \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1=4cm v\u00e0 A2. Bi\u1ebft \u0111\u1ed9 l\u1edbn v\u1eadn t\u1ed1c c\u1ee7a v\u1eadt t\u1ea1i th\u1eddi \u0111i\u1ec3m \u0111\u1ed9ng n\u0103ng c\u1ee7a v\u1eadt b\u1eb1ng 2 l\u1ea7n th\u1ebf n\u0103ng l\u00e0 20cm\/s. Gi\u00e1 tr\u1ecb c\u1ee7a A2 l\u00e0: A. 4cm B. 6cm C. 2 3 cm D. 2 cm C\u00e2u 27: (Minh H\u1ecda-2018) Dao \u0111\u1ed9ng c\u1ee7a m\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 200g l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng D1 v\u00e0 D2. H\u00ecnh v\u1ebd b\u00ean l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a li \u0111\u1ed9 c\u1ee7a D1 v\u00e0 D2 theo th\u1eddi gian. M\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng c\u1ee7a v\u1eadt. Bi\u1ebft c\u01a1 n\u0103ng c\u1ee7a v\u1eadt l\u00e0 22,5 mJ. L\u1ea5y \u03c02=10 Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng D2 c\u00f3 gi\u00e1 tr\u1ecb c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y: A. 5,2 cm B. 5,4cm C. 4,8cm D. 5,7cm C\u00e2u 28: (VDC \u0110H\u2212 2017) Cho D1, D2 v\u00e0 D3 l\u00e0 ba \u0111ao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng c\u00f9ng t\u1ea7n s\u1ed1. Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a D1 v\u00e0 D2 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x12 =3 3cos\uf0e6\uf0e7\uf0e8 \uf077t + \uf070 \uf0f6 (cm). Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p 2 \uf0f7\uf0f8 c\u1ee7a D2 v\u00e0 D3 c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x23 = 3cos\uf077t (cm). Dao \u0111\u1ed9ng D1 ng\u01b0\u1ee3c pha v\u1edbi dao \u0111\u1ed9ng D3. Bi\u00ean \u0111\u1ed9 c\u1ee7a dao \u0111\u1ed9ng D2 c\u00f3 gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t l\u00e0 A. 2,6 cm. B. 2,7 cm. C. 3,6 cm. D. 3,7 cm. C\u00e2u 29: (\u0110H-2019) Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a m\u1ed9t v\u1eadt l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng c\u00f9ng ph\u01b0\u01a1ng c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 3cos\uf0e6\uf0e7\uf0e810t + \uf070\uf0f6 v\u00e0 x2 = A2 cos\uf0e8\uf0e7\uf0e610t \u2212 \uf070 \uf0f6 (A2 > 0, t t\u00ednh b\u1eb1ng gi\u00e2y). T\u1ea1i t = 2 \uf0f7\uf0f8 6 \uf0f8\uf0f7 0, gia t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn l\u00e0 150 3 cm\/s2. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng l\u00e0 A. 3 cm B. 3 2 cm C. 3 3 cm D. 6 cm C\u00e2u 30: (\u0110H-2019) Dao \u0111\u1ed9ng c\u1ee7a m\u1ed9t v\u1eadt l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng c\u00f9ng ph\u01b0\u01a1ng c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 8cos \uf0e6\uf0e7\uf0e810t \u2212 \uf070 \uf0f6 cm v\u00e0 x2 = A2 cos \uf0e6\uf0e7\uf0e810t + \uf070 \uf0f6 cm (A2 > 0, t t\u00ednh theo s). T\u1ea1i t=0, 2 \uf0f7\uf0f8 4 \uf0f7\uf0f8 gia t\u1ed1c c\u1ee7a v\u1eadt c\u00f3 \u0111\u1ed9 l\u1edbn 800cm\/s2. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 A. 4\u221a3cm B. 4cm C. 8cm D. 4\u221a2cm C\u00e2u 31: (Minh H\u1ecda-2020) Dao \u0111\u1ed9ng c\u1ee7a m\u1ed9t v\u1eadt l\u00e0 t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1 5 Hz v\u1edbi c\u00e1c bi\u00ean \u0111\u1ed9 6 cm v\u00e0 8 cm. Bi\u1ebft hai dao \u0111\u1ed9ng ng\u01b0\u1ee3c pha nhau. T\u1ed1c \u0111\u1ed9 c\u1ee7a v\u1eadt c\u00f3 gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i l\u00e0 A. 63 cm\/s B. 4,4 m\/s C. 3,1 m\/s D. 36cm\/s TRANG 91","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 2: T\u1ed4NG H\u1ee2P DAO \u0110\u1ed8NG N\u00c2NG CAO \uf040B\u00c0I TO\u00c1N: Hai v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1 v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0: x1=A1cos(wt + \u03c61) v\u00e0 x2=A2cos(wt + \u03c62) \u2756KI\u1ec2U 1: KHO\u1ea2NG C\u00c1CH GI\u1eeeA HAI V\u1eacT & TH\u1edcI \u0110I\u1ec2M HAI V\u1eacT G\u1eb6P NHAU \u27a2 G\u1ecdi \uf044x = x1 \u2212 x2 = A1cos ( wt + \uf06a1 ) \u2212 A2cos ( wt + \uf06a2 ) = Q.cos ( wt + \uf06a) \u27a2 Ta c\u00f3 th\u1ec3 coi \uf044x = Q.cos (wt + \uf06a) c\u0169ng l\u00e0 1 v\u1eadt \u0111ang dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a. \uf08c Kho\u1ea3ng c\u00e1ch gi\u1eefa hai v\u1eadt tr\u00ean tr\u1ee5c Ox: \u27a2 C\u00f4ng th\u1ee9c kho\u1ea3ng c\u00e1ch: d1 = x1 \u2212 x2 = \uf044x \u27a2Kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t: d1Max = \uf044xmax = Q = A12 + A22 \u2212 2A1.A 2.cos \uf044\uf06a \uf08d Kho\u1ea3ng c\u00e1ch gi\u1eefa hai v\u1eadt trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng \u27a2 C\u00f4ng th\u1ee9c kho\u1ea3ng c\u00e1ch: d2 = d12 + (O1O2 )2 = \uf044x2 + (O1O2 )2 \u27a2 Kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t: d2max = \uf044xmax2 + (O1O2 )2 = Q2 + (O1O2 )2 \uf08e X\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m hai v\u1eadt g\u1eb7p nhau \uf0db x1 = x2 \uf0db \uf044x = Q.cos ( wt + \u03c6) = 0 \u27a2 Ta c\u00f3 th\u1ec3 coi b\u00e0i to\u00e1n t\u00ecm th\u1eddi \u0111i\u1ec3m hai v\u1eadt g\u1eb7p nhau ch\u00ednh l\u00e0 th\u1eddi \u0111i\u1ec3m v\u1eadt \u2206x \u0111ang \u0111i qua VTCB. \u2756 KI\u1ec2U 2: B\u00c0I TO\u00c1N T\u00ccM GI\u00c1 TR\u1eca C\u1ef0C \u0110\u1ea0I, C\u1ef0C TI\u1ec2U C\u1ee6A BI\u00caN \u0110\u1ed8 T\u1ed4NG H\u1ee2P HO\u1eb6C TH\u00c0NH PH\u1ea6N: \u27a2 Ta v\u1ebd gi\u1ea3n \u0111\u1ed3 v\u00e9c - t\u01a1 v\u00e0 \u00e1p d\u1ee5ng \u0111\u1ecbnh lu\u1eadt h\u00e0m sin theo nguy\u00ean t\u00e1c bi\u1ec3u di\u1ec5n bi\u00ean \u0111\u1ed9 c\u1ea7n \u0111i t\u00ecm Max (Min) v\u1edbi m\u1ed9t bi\u00ean \u0111\u1ed9 m\u00e0 \u0111\u1ec1 b\u00e0i \u0111\u00e3 cho bi\u1ebft tr\u01b0\u1edbc gi\u00e1 tr\u1ecb. KI\u1ec2U 1: KHO\u1ea2NG C\u00c1CH GI\u1eeeA HAI V\u1eacT & TH\u1edcI \u0110I\u1ec2M HAI V\u1eacT G\u1eb6P NHAU C\u00e2u 32: Hai ch\u1ea5t \u0111i\u1ec3m M v\u00e0 N c\u00f9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean tr\u1ee5c Ox v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0: x1 = 3cos(2\uf070t \u2212 \uf070) (cm) v\u00e0 x2 = 3cos \uf0e6 2\uf070t \u2212 2\uf070 \uf0f6 (cm). Kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t gi\u1eefa hai v\u1eadt trong \uf0e7\uf0e8 3 \uf0f7\uf0f8 qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng l\u00e0: A. 3cm B. 4cm C. 5cm D. 6cm C\u00e2u 33: Hai ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1 v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0: x1 = 8cos\uf070t (cm) v\u00e0 x2 = 8cos \uf0e6 \uf070t \u2013 \uf070 \uf0f6 (cm). Hai ch\u1ea5t \u0111i\u1ec3m g\u1eb7p nhau l\u1ea7n \u0111\u1ea7u t\u1ea1i th\u1eddi \u0111i\u1ec3m: \uf0e7\uf0e8 3 \uf0f8\uf0f7 A. 1\/6s B. 1\/3s C. 1\/4s D. 1\/2s C\u00e2u 34: Hai \u0111i\u1ec3m s\u00e1ng M v\u00e0 N c\u00f9ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean tr\u1ee5c Ox v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 xM = 4cos \uf0e6 5\uf070t + \uf070 \uf0f6 (cm) v\u00e0 xN = 4cos \uf0e6\uf0e7\uf0e8 5\uf070t + \uf070 \uf0f6 (cm). K\u1ec3 t\u1eeb t=0, th\u1eddi \u0111i\u1ec3m hai \u0111i\u1ec3m s\u00e1ng \uf0e7\uf0e8 3 \uf0f7\uf0f8 12 \uf0f8\uf0f7 c\u00e1ch nhau m\u1ed9t \u0111o\u1ea1n l\u1edbn nh\u1ea5t l\u1ea7n \u0111\u1ea7u l\u00e0: A. 7\/120s B. 1\/30s C. 2\/15s D. 1\/15s TRANG 92","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 35: Hai v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean hai \u0111o\u1ea1n th\u1eb3ng song song c\u1ea1nh nhau, c\u00f9ng m\u1ed9t v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng tr\u00f9ng v\u1edbi g\u1ed1c t\u1ecda \u0111\u1ed9, c\u00f9ng m\u1ed9t tr\u1ee5c t\u1ecda \u0111\u1ed9 song song v\u1edbi \u0111o\u1ea1n th\u1eb3ng \u0111\u00f3 v\u1edbi c\u00e1c ph\u01b0\u01a1ng tr\u00ecnh li \u0111\u1ed9 l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 3cos \uf0e6 5 \uf070t + \uf070 \uf0f6 cm v\u00e0 x1 = 3 3 cos \uf0e6 5 \uf070t + 5\uf070 \uf0f6 cm. T\u1eeb th\u1eddi \u0111i\u1ec3m t = 0, th\u1eddi \uf0e7\uf0e8 3 3 \uf0f7\uf0f8 \uf0e7\uf0e8 3 6 \uf0f7\uf0f8 \u0111i\u1ec3m \u0111\u1ec3 hai v\u1eadt c\u00f3 kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t l\u00e0 bao nhi\u00eau? A. 0,4 s B. 0,5 s C. 0,6 s D. 0,7 s C\u00e2u 36: Hai ch\u1ea5t \u0111i\u1ec3m dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ngtr\u00ean m\u1ed9t tr\u1ee5c Ox c\u00f9ng t\u1ea7n s\u1ed1 v\u00e0 c\u00f9ng v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 3cos(2\uf070t \u2212 \uf070) cm v\u00e0 x2 = 3cos(2\uf070t \u2013 2\uf070 \/ 3) cm. Kho\u1ea3ng th\u1eddi gian nh\u1ecf nh\u1ea5t k\u1ec3 t\u1eeb l\u00fac hai v\u1eadt c\u00e1ch nhau c\u1ef1c \u0111\u1ea1i \u0111\u1ebfn l\u00fac hai v\u1eadt c\u00e1ch nhau b\u1eb1ng 1,5 cm l\u00e0 bao nhi\u00eau. A. 1\/6 s. B. 1\/24 s. C. 1\/8 s. D. 1\/12 s. C\u00e2u 37: Hai \u0111i\u1ec3m s\u00e1ng M v\u00e0 N dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean tr\u1ee5c Ox v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh: xM = 3 3cos(2\uf070t) cm; xN = 6cos \uf0e6 2\uf070t + \uf070 \uf0f6 (cm). K\u1ec3 t\u1eeb th\u1eddi \u0111i\u1ec3m ban \u0111\u1ea7u, x\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m g\u1ea7n nh\u1ea5t M v\u00e0 N g\u1eb7p \uf0e7\uf0e8 12 \uf0f7\uf0f8 nhau l\u1ea7n th\u1ee9 2023 A. 1012,4s B. 1011,9s C. 1011,24 D. 1011,05s C\u00e2u 38: Hai ch\u1ea5t \u0111i\u1ec3m M v\u00e0 N dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean c\u00f9ng m\u1ed9t tr\u1ee5c Ox ( O l\u00e0 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng c\u1ee7a ch\u00fang), coi trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng hai ch\u1ea5t \u0111i\u1ec3m kh\u00f4ng va ch\u1ea1m v\u00e0o nhau. Bi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a ch\u00fang l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = 10cos\uf0e6\uf0e7\uf0e8 4\uf070t + \uf070 \uf0f6 cm v\u00e0 x2 = 10 2cos \uf0e6 4\uf070t + \uf070 \uf0f6 cm. Hai ch\u1ea5t \u0111i\u1ec3m 3 \uf0f8\uf0f7 \uf0e7\uf0e8 12 \uf0f8\uf0f7 c\u00e1ch nhau 5cm \u1edf th\u1eddi \u0111i\u1ec3m l\u1ea7n th\u1ee9 2023 k\u1ec3 t\u1eeb l\u00fac t=0 l\u00e0: A. 2019 s B. 6065 s C. 2023 s D. 2021s 8 24 8 8 C\u00e2u 39: Hai v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean hai \u0111\u01b0\u1eddng th\u1eb3ng c\u00f9ng song song v\u1edbi tr\u1ee5c Ox. H\u00ecnh chi\u1ebfu vu\u00f4ng g\u00f3c c\u1ee7a c\u00e1c v\u1eadt l\u00ean c\u00e1c tr\u1ee5c Ox dao \u0111\u1ed9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x1 = 10cos \uf0e6 2,5\uf070t + \uf070\uf0f6 (cm) v\u00e0 \uf0e7\uf0e8 4 \uf0f7\uf0f8 x2 = 10cos \uf0e6 2,5\uf070t \u2212 \uf070 \uf0f6 (cm) ( t t\u00ednh b\u1eb1ng s). K\u1ec3 t\u1eeb t=0, th\u1eddi \u0111i\u1ec3m h\u00ecnh chi\u1ebfu c\u1ee7a hai v\u1eadt c\u00e1ch \uf0e7\uf0e8 4 \uf0f7\uf0f8 nhau 10cm l\u1ea7n th\u1ee9 2023 l\u00e0: A. 404,1s B. 403,2 s C. 404,5 s D. 404,3 s C\u00e2u 40: (Chuy\u00ean KHTN \u2013 2017) Hai ch\u1ea5t \u0111i\u1ec3m M v\u00e0 N c\u00f3 c\u00f9ng kh\u1ed1i l\u01b0\u1ee3ng, dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng t\u1ea7n s\u1ed1 d\u1ecdc theo hai \u0111\u01b0\u1eddng th\u1eb3ng song song k\u1ec1 nhau v\u00e0 song song v\u1edbi tr\u1ee5c Ox. V\u1ecb tr\u00ed c\u00e2n b\u1eb1ng c\u1ee7a M v\u00e0 N \u0111\u1ec1u n\u1eb1m tr\u00ean m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua g\u1ed1c t\u1ecda \u0111\u1ed9 v\u00e0 vu\u00f4ng g\u00f3c v\u1edbi Ox. Bi\u00ean \u0111\u1ed9 c\u1ee7a M l\u00e0 6 cm, c\u1ee7a N l\u00e0 8 cm. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t gi\u1eefa M v\u00e0 N theo ph\u01b0\u01a1ng Ox l\u00e0 10 cm. M\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. \u1ede th\u1eddi \u0111i\u1ec3m m\u00e0 M c\u00f3 \u0111\u1ed9ng n\u0103ng b\u1eb1ng ba l\u1ea7n th\u1ebf n\u0103ng th\u00ec t\u1ec9 s\u1ed1 gi\u1eefa \u0111\u1ed9ng n\u0103ng c\u1ee7a M v\u00e0 c\u1ee7a N l\u00e0 4 9 27 3 A. B. C. D. 3 16 16 4 TRANG 93","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 41: (VDC-Minh H\u1ecda-2018) Hai con l\u1eafc gi\u1ed1ng h\u1ec7t nhau \u0111\u01b0\u1ee3c treo v\u00e0o hai \u0111i\u1ec3m \u1edf c\u00f9ng \u0111\u1ed9 cao, c\u00e1ch nhau 3cm. K\u00edch th\u00edch cho hai con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t x1 = 3cos( wt ) (cm) v\u00e0 x2 = 6cos \uf0e6 wt + \uf070\uf0f6 (cm). Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng, kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t gi\u1eefa \uf0e7\uf0e8 3 \uf0f8\uf0f7 hai v\u1eadt nh\u1ecf c\u1ee7a c\u00e1c con l\u1eafc b\u1eb1ng: A. 9cm B. 6cm C. 5,2cm D. 8,5cm C\u00e2u 42: (\u0110H-2018) Hai v\u1eadt dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean hai \u0111\u01b0\u1eddng th\u1eb3ng c\u00f9ng song song v\u1edbi tr\u1ee5c Ox. H\u00ecnh chi\u1ebfu vu\u00f4ng g\u00f3c c\u1ee7a c\u00e1c v\u1eadt l\u00ean c\u00e1c tr\u1ee5c Ox dao \u0111\u1ed9ng v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh x1 = 10cos(2,5\uf070t + \uf070 \/ 4) (cm) v\u00e0 x2 = 10cos(2,5\uf070t \u2212 \uf070 \/ 4) (cm) ( t t\u00ednh b\u1eb1ng s). K\u1ec3 t\u1eeb t=0, th\u1eddi \u0111i\u1ec3m h\u00ecnh chi\u1ebfu c\u1ee7a hai v\u1eadt c\u00e1ch nhau 10cm l\u1ea7n th\u1ee9 2018 l\u00e0: A. 806,9 s B. 403,2 s C. 807,2 s D. 403,5 s C\u00e2u 43: (VDC\u2013Minh H\u1ecda 2019) Hai \u0111i\u1ec3m s\u00e1ng dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi c\u00f9ng bi\u00ean \u0111\u1ed9 tr\u00ean m\u1ed9t \u0111o\u1ea1n th\u1eb3ng, quanh v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 0. C\u00e1c pha c\u1ee7a hai dao \u0111\u1ed9ng \u1edf th\u1eddi \u0111i\u1ec3m t l\u00e0 \u03b11 v\u00e0 \u03b12. H\u00ecnh b\u00ean l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a \u03b11 v\u00e0 c\u1ee7a \u03b12 theo th\u1eddi gian. T\u00ednh t\u1eeb th\u1eddi \u0111i\u1ec3m t=0, th\u1eddi \u0111i\u1ec3m hai \u0111i\u1ec3m s\u00e1ng g\u1eb7p nhau l\u1ea7n \u0111\u1ea7u l\u00e0: A. 0,15s B. 0,3s C. 0,2s D. 0,25s C\u00e2u 44: (VDC-Chuy\u00ean Vinh-2020) Hai con l\u1eafc l\u00f2 xo gi\u1ed1ng h\u1ec7t nhau dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang d\u1ecdc theo hai \u0111\u01b0\u1eddng th\u1eb3ng song song c\u1ea1nh nhau v\u00e0 song song v\u1edbi tr\u1ee5c Ox. Bi\u00ean \u0111\u1ed9 c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t l\u00e0 A1 = 4 cm, c\u1ee7a con l\u1eafc th\u1ee9 hai l\u00e0 A2 = 4 3 cm, con l\u1eafc th\u1ee9 hai dao \u0111\u1ed9ng s\u1edbm pha h\u01a1n con l\u1eafc th\u1ee9 nh\u1ea5t. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng kho\u1ea3ng c\u00e1ch l\u1edbn nh\u1ea5t gi\u1eefa hai v\u1eadt d\u1ecdc theo tr\u1ee5c Ox l\u00e0 a = 4 cm. Khi \u0111\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc th\u1ee9 nh\u1ea5t c\u1ef1c \u0111\u1ea1i l\u00e0 W th\u00ec \u0111\u1ed9ng n\u0103ng c\u1ee7a con l\u1eafc th\u1ee9 hai l\u00e0 A. W B. 3 W C. 9 W D. 2 W 4 4 3 KI\u1ec2U 2: B\u00c0I TO\u00c1N C\u1ef0C TR\u1eca MAX, MIN C\u00e2u 45: Hai dao \u0111\u1ed9ng c\u00f9ng ph\u01b0\u01a1ng l\u1ea7n l\u01b0\u1ee3t c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x1 = A1cos \uf0e6 \uf070t + \uf070 \uf0f6 cm v\u00e0 \uf0e7\uf0e8 6 \uf0f8\uf0f7 x2 = 6cos\uf0e6\uf0e7\uf0e8 \uf070t \u2013 \uf070 \uf0f6 cm. Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh x = Acos(\uf070t + \uf06a) Thay \u0111\u1ed5i A1 sao 2 \uf0f7\uf0f8 cho bi\u00ean \u0111\u1ed9 A \u0111\u1ea1t gi\u00e1 tr\u1ecb c\u1ef1c ti\u1ec3u th\u00ec gi\u00e1 tr\u1ecb c\u1ee7a \uf06a l\u00e0: A. \u2013\u03c0\/6 B. \u03c0 C. \u2013\u03c0\/3 D. 0 C\u00e2u 46: V\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a x1 = A1cos \uf0e6 5\uf070t \u2013 \uf070 \uf0f6 cm v\u00e0 \uf0e7\uf0e8 6 \uf0f7\uf0f8 x2 = A2cos \uf0e6 5\uf070t + \uf070\uf0f6 cm. Bi\u1ebft bi\u00ean \u0111\u1ed9 t\u1ed5ng h\u1ee3p A= 3 cm. \u0110\u1ec3 bi\u00ean \u0111\u1ed9 A1 c\u00f3 gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i th\u00ec \uf0e7\uf0e8 2 \uf0f7\uf0f8 bi\u00ean \u0111\u1ed9 A2 b\u1eb1ng: A. 1cm B. 2cm C. 3cm D. 4cm TRANG 94","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 47: M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi 2 dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng x1 = A1cos \uf0e6\uf0e7\uf0e810\uf070t + \uf070 \uf0f6 cm v\u00e0 3 \uf0f7\uf0f8 x2 = A2cos \uf0e6 10\uf070t \u2013 \uf070 \uf0f6 cm. Ph\u01b0\u01a1ng tr\u00ecnh t\u1ed5ng h\u1ee3p l\u00e0 x = 5cos(10\uf070t + \uf06a) cm. Bi\u1ebft bi\u00ean \u0111\u1ed9 dao \uf0e7\uf0e8 2 \uf0f8\uf0f7 \u0111\u1ed9ng A2 c\u00f3 gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t. Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a A2 l\u00e0: A. 4cm B. 5cm C. 8cm D. 10cm C\u00e2u 48: Hai ch\u1ea5t \u0111i\u1ec3m th\u1ef1c hi\u1ec7n dao \u0111\u1ed9ng tr\u00ean hai \u0111\u01b0\u1eddng th\u1eb1ng song song, n\u1eb1m ngang, c\u00f3 g\u1ed1c t\u1ecda \u0111\u1ed9 n\u1eb1m tr\u00ean \u0111\u01b0\u1eddng th\u1eb3n c\u00f3 ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng. Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a m\u1ed7i v\u1eadt t\u01b0\u01a1ng \u1ee9ng l\u00e0 x1 = A1cos \uf0e6 \uf070t + \uf070 \uf0f6 , x2 = 12cos\uf0e6\uf0e7\uf0e8 \uf070t + 2\uf070 \uf0f6 . G\u1ed1c th\u1eddi gian l\u00e0 l\u00fac v\u1eadt b\u1eaft \u0111\u1ea7u chuy\u1ec3n \u0111\u1ed9ng, \uf0e7\uf0e8 3 \uf0f7\uf0f8 3 \uf0f7\uf0f8 kho\u1ea3ng c\u00e1ch tr\u00ean ph\u01b0\u01a1ng ngang gi\u1eefa hai v\u1eadt \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1edfi ph\u01b0\u01a1ng tr\u00ecnh d = Acos(\uf070t + \uf06a). Thay \u0111\u1ed5i A1 cho \u0111\u1ebfn khi bi\u00ean \u0111\u1ed9 A \u0111\u1ea1t gi\u00e1 tr\u1ecb c\u1ef1c ti\u1ec3u th\u00ec: A. A=6cm v\u00e0 A1=6 3 cm B. A=12cm v\u00e0 A1=6cm C. A=12cm v\u00e0 A1=6 3 cm D. A=6 3 cm v\u00e0 A1=6cm C\u00e2u 49: M\u1ed9t v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u1ed3ng th\u1eddi hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = A1cos \uf0e6 wt + \uf070 \uf0f6 (cm) v\u00e0 x2 = A 2cos \uf0e6 wt + 5\uf070 \uf0f6 (cm). Ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng c\u1ee7a v\u1eadt l\u00e0 \uf0e7\uf0e8 6 \uf0f7\uf0f8 \uf0e7\uf0e8 6 \uf0f7\uf0f8 x = 3 3cos(wt + \uf06a). \u0110\u1ec3 bi\u00ean \u0111\u1ed9 A2 c\u00f3 gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i th\u00ec bi\u00ean \u0111\u1ed9 A1 b\u1eb1ng: A. 6cm B. 3 2 cm C. 6 2 cm D. 3cm C\u00e2u 50: M\u1ed9t ch\u1ea5t \u0111i\u1ec3m c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng, c\u00f9ng t\u1ea7n s\u1ed1, c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = A1cos(wt + \uf06a1) cm v\u00e0 x2 = A2cos(wt + \uf06a2 ) cm. Bi\u1ebft r\u1eb1ng 9x12+16x22=144 (cm2). L\u1ef1c k\u00e9o v\u1ec1 c\u1ef1c \u0111\u1ea1i l\u00e0 0,4N. Gi\u00e1 tr\u1ecb w g\u1ea7n gi\u00e1 tr\u1ecb n\u00e0o nh\u1ea5t sau \u0111\u00e2y: A. 40 rad\/s B. 30rad\/s C. 20rad\/s D. 10 rad\/s C\u00e2u 51: (VDC) Cho hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng v\u1edbi c\u00e1c ph\u01b0\u01a1ng tr\u00ecnh l\u1ea7n l\u01b0\u1ee3t l\u00e0 x1 = A1cos \uf0e6 \uf077t + \uf070 \uf0f6 (cm) v\u00e0 x2 = A2cos \uf0e6 \uf077t \u2212 \uf070 \uf0f6 (cm). Dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p c\u1ee7a hai dao \u0111\u1ed9ng \uf0e7\uf0e8 9 \uf0f7\uf0f8 \uf0e7\uf0e8 2 \uf0f8\uf0f7 n\u00e0y c\u00f3 ph\u01b0\u01a1ng tr\u00ecnh l\u00e0 x = 15cos(\uf077t + \uf06a) (cm). Gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i c\u1ee7a (Al + A2) g\u1ea7n gi\u00e1 tr\u1ecb n\u00e0o nh\u1ea5t sau \u0111\u00e2y? A. 25cm. B. 20 cm. C. 40 cm. D. 35 cm. C\u00e2u 52: (VDC - S\u1edf H\u00e0 N\u1ed9i 2018) Cho x1 = A1 cos \uf0e6\uf0e7\uf0e8 \uf077t + \uf070 \uf0f6 cm v\u00e0 x2 = A2 cos \uf0e6 \uf077t \u2212 \uf070 \uf0f6 cm l\u00e0 hai 3 \uf0f7\uf0f8 \uf0e7\uf0e8 4 \uf0f7\uf0f8 ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a hai dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a c\u00f9ng ph\u01b0\u01a1ng. Bi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh dao \u0111\u1ed9ng t\u1ed5ng h\u1ee3p l\u00e0 x = 5cos(\uf077t + \uf06a) cm. \u0110\u1ec3 t\u1ed5ng bi\u00ean \u0111\u1ed9 c\u1ee7a c\u00e1c dao \u0111\u1ed9ng th\u00e0nh ph\u1ea7n (A1 + A2) c\u1ef1c \u0111\u1ea1i th\u00ec \u03c6 c\u00f3 gi\u00e1 tr\u1ecb l\u00e0 \uf070 \uf070 C. 5\uf070 . \uf070 A. . B. . 12 D. . 6 24 12 TRANG 95","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 D\u1ea0NG 3: DAO \u0110\u1ed8NG T\u1eaeT D\u1ea6N QU\u00c3NG \u0110\u01af\u1edcNG BI\u00caN \u0110\u1ed8 \u2756 \u0110\u1ed9 gi\u1ea3m bi\u00ean \u0111\u1ed9 trong: \u2756 Qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt \u0111i \u0111\u01b0\u1ee3c sau m\u1ed7i n\u1eeda chu k\u00ec: \u27a2 M\u1ed9t ph\u1ea7n t\u01b0 chu k\u00ec: \uf044A T = \uf06dmg S = 2n.A \u2212 n2.\uf044AT ( n: s\u1ed1 n\u1eeda chu k\u1ef3 v\u1eadt th\u1ef1c hi\u1ec7n) K 4 2 \u27a2 M\u1ed9t n\u1eeda chu k\u00ec: \uf044A T = 2\uf06dmg \u2756 Qu\u00e3ng \u0111\u01b0\u1eddng m\u00e0 v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c cho \u0111\u1ebfn khi K d\u1eebng l\u1ea1i: S = K.A2 2 2\uf06dmg \u27a2 M\u1ed9t chu k\u00ec: \uf044AT = 4\uf06dmg K \u2756 C\u00f4ng th\u1ee9c \u201c\u0111\u1ed9c\u201d \u0111\u1ec3 t\u00ednh gi\u00e1 tr\u1ecb g\u1ea7n \u0111\u00fang nh\u1ea5t t\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a m\u1ed9t v\u1eadt trong qu\u00e1 tr\u00ecnh dao \u2756 S\u1ed1 dao \u0111\u1ed9ng v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c cho \u0111\u1ebfn khi d\u1eebng l\u1ea1i: N = A \u0111\u1ed9ng: \uf044AT vTB =S = w.A = vmax \u2756 Th\u1eddi gian v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c cho \u0111\u1ebfn khi d\u1eebng \uf044t \uf070\uf070 l\u1ea1i: \uf044t = N.T \u2756 Li \u0111\u1ed9 c\u1ef1c \u0111\u1ea1i (bi\u00ean \u0111\u1ed9 ) so v\u1edbi VTCB O ban \u0111\u1ea7u \u2756 M\u1ed1i quan h\u1ec7 gi\u1eefa \u0111\u1ed9 gi\u1ea3m bi\u00ean \u0111\u1ed9 v\u1edbi \u0111\u1ed9 gi\u1ea3m sau m\u1ed7i n\u1eeda chu k\u00ec: c\u01a1 n\u0103ng trong M\u1ed8T CHU K\u00cc: \uf044W \uf0bb 2 \uf044A WA An = A \u2212 n.\uf044AT (n: s\u1ed1 n\u1eeda chu k\u1ef3 v\u1eadt th\u1ef1c hi\u1ec7n) 2 C\u00e2u 53: M\u1ed9t v\u1eadt dao \u0111\u1ed9ng t\u1eaft d\u1ea7n c\u00f3 c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng gi\u1ea3m li\u00ean t\u1ee5c theo th\u1eddi gian l\u00e0 A. Bi\u00ean \u0111\u1ed9 v\u00e0 gia t\u1ed1c B. Bi\u00ean \u0111\u1ed9 v\u00e0 n\u0103ng l\u01b0\u1ee3ng C. Li \u0111\u1ed9 v\u00e0 t\u1ed1c \u0111\u1ed9 D. Bi\u00ean \u0111\u1ed9 v\u00e0 t\u1ed1c \u0111\u1ed9 C\u00e2u 54: Trong c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00f4ng thay \u0111\u1ed5i theo th\u1eddi gian trong dao \u0111\u1ed9ng t\u1eaft d\u1ea7n A. \u0110\u1ed9ng n\u0103ng B. C\u01a1 n\u0103ng C. Bi\u00ean \u0111\u1ed9 D. T\u1ea7n s\u1ed1 C\u00e2u 55: (\u0110H-2017) Khi n\u00f3i v\u1ec1 dao \u0111\u1ed9ng t\u1eaft d\u1ea7n c\u1ee7a m\u1ed9t v\u1eadt, ph\u00e1t bi\u1ec3u n\u00e0o sau \u0111\u00e2y l\u00e0 \u0111\u00fang: A. Li \u0111\u1ed9 c\u1ee7a v\u1eadt lu\u00f4n gi\u1ea3m d\u1ea7n theo th\u1eddi gian. B. Gia t\u1ed1c c\u1ee7a v\u1eadt lu\u00f4n gi\u1ea3m d\u1ea7n theo th\u1eddi gian. C. V\u1eadn t\u1ed1c c\u1ee7a v\u1eadt lu\u00f4n gi\u1ea3m d\u1ea7n theo th\u1eddi gian. D. Bi\u00ean \u0111\u1ed9 c\u1ee7a dao \u0111\u1ed9ng gi\u1ea3m d\u1ea7n theo th\u1eddi gian. C\u00e2u 56: M\u1ed9t con l\u1eafc dao \u0111\u1ed9ng t\u1eaft d\u1ea7n ch\u1eadm. C\u1ee9 sau m\u1ed7i chu k\u00ec bi\u00ean \u0111\u1ed9 gi\u1ea3m 3%. Ph\u1ea7n n\u0103ng l\u01b0\u1ee3ng c\u1ee7a con l\u1eafc m\u1ea5t \u0111i trong m\u1ed9t dao \u0111\u1ed9ng to\u00e0n ph\u1ea7n l\u00e0: A. 3% B. 6% C. 9% D. 94% C\u00e2u 57: C\u01a1 n\u0103ng c\u1ee7a m\u1ed9t dao \u0111\u1ed9ng t\u1eaft d\u1ea7n ch\u1eadm gi\u1ea3m 5% sau m\u1ed7i chu k\u00ec. Sau m\u1ed7i chu k\u00ec bi\u00ean \u0111\u1ed9 gi\u1ea3m A. 5% B. 2,5% C. 10% D. 2,24% C\u00e2u 58: (\u0110H-2017) M\u1ed9t con l\u1eafc l\u00f2 xo dao \u0111\u1ed9ng t\u1eaft d\u1ea7n tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. C\u1ee9 sau m\u1ed7i chu k\u00ec bi\u00ean \u0111\u1ed9 gi\u1ea3m 2%. G\u1ed1c th\u1ebf n\u0103ng t\u1ea1i v\u1ecb tr\u00ed c\u1ee7a v\u1eadt m\u00e0 l\u00f2 xo kh\u00f4ng bi\u1ebfn d\u1ea1ng. Ph\u1ea7n tr\u0103m c\u01a1 n\u0103ng c\u1ee7a con l\u1eafc b\u1ecb m\u1ea5t \u0111i trong hai dao \u0111\u1ed9ng to\u00e0n ph\u1ea7n li\u00ean ti\u1ebfp c\u00f3 gi\u00e1 tr\u1ecb g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb: A. 7% B. 4% C. 10% D. 8% C\u00e2u 59: M\u1ed9t con l\u1eafc l\u00f2 xo th\u1eb3ng \u0111\u1ee9ng g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m, m\u1ed9t \u0111\u1ea7u c\u1ed1 \u0111\u1ecbnh, m\u1ed9t \u0111\u1ea7u g\u1eafn v\u1edbi v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 0,5kg. Ban \u0111\u1ea7u k\u00e9o v\u1eadt theo ph\u01b0\u01a1ng th\u1eb3ng \u0111\u1ee9ng kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 5cm r\u1ed3i bu\u00f4ng nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng. Trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng v\u1eadt lu\u00f4n ch\u1ecbu t\u00e1c d\u1ee5ng c\u1ee7a l\u1ef1c c\u1ea3n c\u00f3 \u0111\u1ed9 l\u1edbn b\u1eb1ng 1\/100 tr\u1ecdng l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean v\u1eadt. Coi bi\u00ean \u0111\u1ed9 c\u1ee7a v\u1eadt gi\u1ea3m \u0111\u1ec1u trong t\u1eebng chu k\u00ec, l\u1ea5y g=10m\/s2. S\u1ed1 l\u1ea7n v\u1eadt qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng k\u1ec3 t\u1eeb khi th\u1ea3 v\u1eadt \u0111\u1ebfn khi n\u00f3 d\u1eebng h\u1eb3n: A. 25 B. 50 C. 30 D. 20 TRANG 96","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 60: M\u1ed9t con l\u1eafc l\u00f2 xo, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g, l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m dao \u0111\u1ed9ng tr\u00ean m\u1eb7t ph\u1eb3ng ngang v\u1edbi bi\u00ean \u0111\u1ed9 ban \u0111\u1ea7u l\u00e0 10cm. L\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng g=10m\/s2. Bi\u1ebft h\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng ngang l\u00e0 0,1. S\u1ed1 dao \u0111\u1ed9ng v\u1eadt th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c \u0111\u1ebfn l\u00fac d\u1eebng l\u1ea1i l\u00e0: A. 25 B. 50 C. 30 D. 20 C\u00e2u 61: M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g n\u1ed1i v\u1edbi m\u1ed9t l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 80N\/m. \u0110\u1ea7u con l\u1ea1i c\u1ee7a l\u00f2 xo \u0111\u01b0\u1ee3c g\u1eafn c\u1ed1 \u0111\u1ecbnh, sao cho v\u1eadt c\u00f3 th\u1ec3 dao \u0111\u1ed9ng tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. Ng\u01b0\u1eddi ta k\u00e9o v\u1eadt ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng 3cm v\u00e0 truy\u1ec1n cho n\u00f3 v\u1eadn t\u1ed1c 80 2 cm\/s. L\u1ea5y g=10m\/s2. T\u00ednh h\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng n\u1eb1m ngang bi\u1ebft v\u1eadt ch\u1ec9 dao \u0111\u1ed9ng \u0111\u01b0\u1ee3c 10 chu k\u00ec th\u00ec d\u1eebng h\u1eb3n A. 0,5 B. 0,2 C. 0,05 D. 0,1 C\u00e2u 62: M\u1ed9t v\u1eadt kh\u1ed1i l\u01b0\u1ee3ng 200g n\u1ed1i v\u1edbi m\u1ed9t l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 80N\/m \u0111\u1ea7u con l\u1ea1i l\u00f2 xo g\u1eafn c\u1ed1 \u0111\u1ecbnh sao cho v\u1eadt dao \u0111\u1ed9ng tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. K\u00e9o v\u1eadt ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n 10cm r\u1ed3i bu\u00f4ng tay kh\u00f4ng v\u1eadn t\u1ed1c ban \u0111\u1ea7u. L\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10m\/s2. Khi h\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng n\u1eb1m ngang l\u00e0 0,1. T\u00ecm th\u1eddi gian t\u1eeb l\u00fac v\u1eadt b\u1eaft \u0111\u1ea7u dao \u0111\u1ed9ng \u0111\u1ebfn l\u00fac d\u1eebng l\u1ea1i A. 2s B. 1s C. 2\u03c0 s D. \u03c0 s C\u00e2u 63: Con l\u1eafc l\u00f2 xo n\u1eb1m ngang g\u1ed3m l\u00f2 xo nh\u1eb9 c\u00f3 \u0111\u1ed9 c\u1ee9ng k=100N\/m, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=100g. K\u00e9o v\u1eadt \u0111\u1ebfn v\u1ecb tr\u00ed m\u00e0 l\u00f2 xo gi\u00e3n m\u1ed9t \u0111o\u1ea1n 4cm r\u1ed3i th\u1ea3 nh\u1eb9. Sau khi qua v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng l\u1ea7n th\u1ee9 nh\u1ea5t, do c\u00f3 ma s\u00e1t n\u00ean l\u00f2 xo ch\u1ec9 b\u1ecb n\u00e9n c\u1ef1c \u0111\u1ea1i l\u00e0 3,96cm. L\u1ea5y g=10m\/s2. H\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 s\u00e0n l\u00e0: A. 0,04 B. 0,02 C. 0,01 D. 0,005 C\u00e2u 64: Con l\u1eafc l\u00f2 xo n\u1eb1m ngang g\u1ed3m v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=400g, l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=100N\/m. K\u00e9o v\u1eadt kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n 3cm r\u1ed3i th\u1ea3 nh\u1eb9. H\u1ec7 s\u00f3 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng ngang l\u00e0 0,005. L\u1ea5y g=10m\/s2. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u00f2n l\u1ea1i sau chu k\u00ec dao \u0111\u1ed9ng \u0111\u1ea7u ti\u00ean l\u00e0: A. 2,99cm B. 2,96cm C. 2,92cm D. 2,89 cm C\u00e2u 65: M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 0,02kg v\u00e0 l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=1N\/m. V\u1eadt nh\u1ecf \u0111\u01b0\u1ee3c \u0111\u1eb7t tr\u00ean gi\u00e1 \u0111\u1ee1 c\u1ed1 \u0111\u1ecbnh n\u1eb1m ngang, d\u1ecdc theo tr\u1ee5c l\u00f2 xo. H\u1ec7 s\u1ed1 m\u00e0 s\u00e1t tr\u01b0\u1ee3t gi\u1eefa gi\u00e1 \u0111\u1ee1 v\u00e0 v\u1eadt nh\u1ecf l\u00e0 0,1. Ban \u0111\u1ea7u gi\u1eef v\u1eadt \u1edf v\u1ecb tr\u00ed l\u00f2 xo n\u00e9n 10cm r\u1ed3i th\u1ea3 nh\u1eb9 \u0111\u1ec3 con l\u1eafc dao \u0111\u1ed9ng t\u1eaft d\u1ea7n. L\u1ea5y g=10m\/s2. T\u1ed1c \u0111\u1ed9 l\u1edbn nh\u1ea5t v\u1eadt nh\u1ecf \u0111\u1ea1t \u0111\u01b0\u1ee3c trong qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng l\u00e0: A. 10 30 cm\/s B. 20 6 cm\/s C. 40 2 cm\/s D. 40 3 cm\/s C\u00e2u 66: M\u1ed9t CLLX n\u1eb1m ngang g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng k=20N\/m v\u00e0 v\u1eadt n\u1eb7ng m=100g. T\u1eeb VTCB k\u00e9o v\u1eadt ra 1 \u0111o\u1ea1n 6cm r\u1ed3i truy\u1ec1n v\u1eadn t\u1ed1c 20 14 cm\/s h\u01b0\u1edbng v\u1ec1 v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. Bi\u1ebft r\u1eb1ng h\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng n\u1eb1m ngang l\u00e0 0,4. L\u1ea5y g=10m\/s2. T\u1ed1c \u0111\u1ed9 c\u1ef1c \u0111\u1ea1i c\u1ee7a v\u1eadt sau khi truy\u1ec1n v\u1eadn t\u1ed1c l\u00e0: A. 20 22 cm\/s B. 80 2 cm\/s C. 20 10 cm\/s D. 60 2 cm\/s C\u00e2u 67: Con l\u1eafc l\u00f2 xo n\u1eb1m ngang c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m, m=100g. K\u00e9o v\u1eadt cho l\u00f2 xo d\u00e3n 2cm r\u1ed3i bu\u00f4ng nh\u1eb9 cho v\u1eadt dao \u0111\u1ed9ng. Bi\u1ebft h\u1ec7 s\u1ed1 ma s\u00e1t l\u00e0 2.10-2. Xem con l\u1eafc dao \u0111\u1ed9ng t\u1eaft d\u1ea7n ch\u1eadm. L\u1ea5y g=10m\/s2. Qu\u00e3ng \u0111\u01b0\u1eddng v\u1eadt \u0111i \u0111\u01b0\u1ee3c trong 4 chu k\u00ec \u0111\u1ea7u ti\u00ean l\u00e0: A. 32cm B. 34,56cm C. 100cm D. 29,44cm C\u00e2u 68: M\u1ed9t v\u1eadt c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 100g \u0111\u01b0\u1ee3c n\u1ed1i v\u1edbi m\u1ed9t l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 100N\/m. \u0110\u1ea7u c\u00f2n l\u1ea1i c\u1ee7a l\u00f2 xo g\u1eafn c\u1ed1 \u0111\u1ecbnh, sao cho v\u1eadt c\u00f3 th\u1ec3 dao \u0111\u1ed9ng tr\u00ean m\u1eb7t ph\u1eb3ng n\u1eb1m ngang. K\u00e9o v\u1eadt ra kh\u1ecfi v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng m\u1ed9t \u0111o\u1ea1n 8cm r\u1ed3i bu\u00f4ng nh\u1eb9. L\u1ea5y gia t\u1ed1c tr\u1ecdng tr\u01b0\u1eddng 10m\/s2. Khi h\u1ec7 s\u1ed1 ma s\u00e1t gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng n\u1eb1m ngang l\u00e0 0,2. Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1ee7a v\u1eadt sau 5 chu k\u00ec dao \u0111\u1ed9ng l\u00e0 A. 2cm B. 6cm C. 5cm D. 4cm TRANG 97","CH\u01af\u01a0NG 1: DAO \u0110\u1ed8NG \u0110I\u1ec0U H\u00d2A - CH\u1ee6 \u0110\u1ec0 4 C\u00e2u 69: M\u1ed9t con l\u1eafc l\u00f2 xo b\u1ed1 tr\u00ed n\u1eb1m ngang, v\u1eadt n\u1eb7ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m=100g, l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng K=160N\/m. L\u1ea5y g=10m\/s2. Khi v\u1eadt \u0111ang \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng, ng\u01b0\u1eddi ta truy\u1ec1n cho v\u1eadt v\u1eadn t\u1ed1c vo=2m\/s2 theo ph\u01b0\u01a1ng ngang \u0111\u1ec3 v\u1eadt dao \u0111\u1ed9ng. Do gi\u1eefa v\u1eadt v\u00e0 m\u1eb7t ph\u1eb3ng n\u1eb1m ngang c\u00f3 ma s\u00e1t v\u1edbi h\u1ec7 s\u1ed1 ma s\u00e1t \uf06d = 0,01 n\u00ean dao \u0111\u1ed9ng c\u1ee7a v\u1eadt s\u1ebd t\u1eaft d\u1ea7n. T\u1ed1c \u0111\u1ed9 trung b\u00ecnh c\u1ee7a v\u1eadt trong su\u1ed1t qu\u00e1 tr\u00ecnh dao \u0111\u1ed9ng g\u1ea7n nh\u1ea5t v\u1edbi gi\u00e1 tr\u1ecb n\u00e0o sau \u0111\u00e2y: A. 63,67cm\/s B. 60cm\/s C. 65,3cm\/s D. 68,6 cm\/s D\u1ea0NG 4: DAO \u0110\u1ed8NG C\u01af\u1ee0NG B\u1ee8C & HI\u1ec6N T\u01af\u1ee2NG C\u1ed8NG H\u01af\u1edeNG \u2756 \u0110\u1ed1i v\u1edbi b\u00e0i to\u00e1n v\u1ec1 so s\u00e1nh bi\u00ean \u0111\u1ed9 trong dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c, c\u00e1c em ghi nh\u1edb \u0111\u1ed3 th\u1ecb c\u1ed9ng h\u01b0\u1edfng b\u00ean d\u01b0\u1edbi l\u00e0 s\u1ebd gi\u1ea3i quy\u1ebft \u0111\u01b0\u1ee3c m\u1ecdi b\u00e0i to\u00e1n thu\u1ed9c d\u1ea1ng n\u00e0y \u2756 M\u1ed9t v\u1eadt dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c d\u01b0\u1edbi t\u00e1c d\u1ee5ng c\u1ee7a ngo\u1ea1i l\u1ef1c tu\u1ea7n ho\u00e0n. Khi thay \u0111\u1ed5i t\u1ea7n s\u1ed1 c\u1ee7a ngo\u1ea1i l\u1ef1c l\u1ea7n l\u01b0\u1ee3t f= f1 ho\u1eb7c f=f2 th\u00ec bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c l\u1ea7n l\u01b0\u1ee3t l\u00e0 A1 v\u00e0 A2. \u2756 N\u1ebfu f = fo th\u00ec x\u1ea3y ra hi\u1ec7n t\u01b0\u1ee3ng c\u1ed9ng h\u01b0\u1edfng c\u01a1, khi \u0111\u00f3 bi\u00ean \u0111\u1ed9 c\u1ee7a dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c \u0111\u1ea1t gi\u00e1 tr\u1ecb c\u1ef1c \u0111\u1ea1i C\u00e2u 70: (\u0110H - 2020) M\u1ed9t con l\u1eafc \u0111\u01a1n c\u00f3 chi\u1ec1u d\u00e0i 50 cm \u0111ang dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c v\u1edbi bi\u00ean \u0111\u1ed9 g\u00f3c nh\u1ecf, t\u1ea1i n\u01a1i c\u00f3 g = 10 m\/s2. Khi c\u00f3 c\u1ed9ng h\u01b0\u1edfng, con l\u1eafc dao \u0111\u1ed9ng \u0111i\u1ec1u h\u00f2a v\u1edbi chu k\u00ec l\u00e0 A. 0,85 s. B. 1,05 s. C. 1,40 s. D. 0,71 s. C\u00e2u 71: (Minh H\u1ecda-2019) Th\u1ef1c hi\u1ec7n th\u00ed nghi\u1ec7m v\u1ec1 dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c nh\u01b0 h\u00ecnh v\u1ebd b\u00ean. N\u0103m con l\u1eafc \u0111\u01a1n: (1), (2), (3), (4) v\u00e0 M ( M l\u00e0 con l\u1eafc \u0111i\u1ec1u khi\u1ec3n) \u0111\u01b0\u1ee3c treo tr\u00ean m\u1ed9t s\u1ee3i d\u00e2y. Ban \u0111\u1ea7u h\u1ec7 \u0111ang \u0111\u1ee9ng y\u00ean \u1edf v\u1ecb tr\u00ed c\u00e2n b\u1eb1ng. K\u00edch th\u00edch M dao \u0111\u1ed9ng nh\u1ecf trong m\u1eb7t ph\u1eb3ng vu\u00f4ng g\u00f3c v\u1edbi m\u1eb7t ph\u1eb3ng h\u00ecnh v\u1ebd th\u00ec c\u00e1c con l\u1eafc c\u00f2n l\u1ea1i dao \u0111\u1ed9ng theo. Kh\u00f4ng k\u1ec3 M, con l\u1eafc dao \u0111\u1ed9ng m\u1ea1nh nh\u1ea5t l\u00e0: A. Con l\u1eafc (2) B. Con l\u1eafc (1) C. Con l\u1eafc (3) D. Con l\u1eafc (4) C\u00e2u 72: (Chuy\u00ean KHTN-2020)M\u1ed9t con l\u1eafc l\u00f2 xo c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng 200 g dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c \u1ed5n \u0111\u1ecbnh d\u01b0\u1edbi t\u00e1c d\u1ee5ng c\u1ee7a ngo\u1ea1i l\u1ef1c bi\u1ebfn thi\u00ean \u0111i\u1ec1u ho\u00e0 v\u1edbi t\u1ea7n s\u1ed1 f. \u0110\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a bi\u00ean \u0111\u1ed9 v\u00e0o t\u1ea7n s\u1ed1 c\u1ee7a ngo\u1ea1i l\u1ef1c t\u00e1c d\u1ee5ng l\u00ean h\u1ec7 c\u00f3 d\u1ea1ng nh\u01b0 h\u00ecnh v\u1ebd. L\u1ea5y \uf0702 = 10 . \u0110\u1ed9 c\u1ee9ng c\u1ee7a l\u00f2 xo A. 50 N\/m B. 32 N\/m C. 42,25 N\/m D. 80 N\/m C\u00e2u 73: (Minh H\u1ecda- 2020) M\u1ed9t con l\u1eafc l\u00f2 xo \u0111ang th\u1ef1c hi\u1ec7n dao \u0111\u1ed9ng c\u01b0\u1ee1ng b\u1ee9c d\u01b0\u1edbi t\u00e1c d\u1ee5ng c\u1ee7a ngo\u1ea1i l\u1ef1c c\u01b0\u1ee1ng b\u1ee9c v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh: F = 0, 25cos(4\uf070t ) (N) (t t\u00ednh b\u1eb1ng s). Con l\u1eafc dao \u0111\u1ed9ng v\u1edbi t\u1ea7n s\u1ed1 g\u00f3c l\u00e0 A. 4\uf070 rad\/s B. 0,5 rad\/s C. 2\uf070 rad\/s D. 0, 25 rad\/s C\u00e2u 74: (\u0110H \u2212 2017) M\u1ed9t con l\u1eafc l\u00f2 xo g\u1ed3m l\u00f2 xo c\u00f3 \u0111\u1ed9 c\u1ee9ng 100 N\/m v\u00e0 v\u1eadt nh\u1ecf c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng m. T\u00e1c d\u1ee5ng l\u00ean v\u1eadt ngo\u1ea1i l\u1ef1c F = 20cos10\u03c0t (N) (t t\u00ednh b\u1eb1ng s) d\u1ecdc theo tr\u1ee5c l\u00f2 xo th\u00ec x\u1ea3y ra hi\u1ec7n t\u01b0\u1ee3ng c\u1ed9ng h\u01b0\u1edfng. L\u1ea5y \u03c02 = 10. Gi\u00e1 tr\u1ecb c\u1ee7a m l\u00e0 A. 100g B. 1kg C. 250g D. 0,4 kg TRANG 98"]
Search
Read the Text Version
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 21
- 22
- 23
- 24
- 25
- 26
- 27
- 28
- 29
- 30
- 31
- 32
- 33
- 34
- 35
- 36
- 37
- 38
- 39
- 40
- 41
- 42
- 43
- 44
- 45
- 46
- 47
- 48
- 49
- 50
- 51
- 52
- 53
- 54
- 55
- 56
- 57
- 58
- 59
- 60
- 61
- 62
- 63
- 64
- 65
- 66
- 67
- 68
- 69
- 70
- 71
- 72
- 73
- 74
- 75
- 76
- 77
- 78
- 79
- 80
- 81
- 82
- 83
- 84
- 85
- 86
- 87
- 88
- 89
- 90
- 91
- 92
- 93
- 94
- 95
- 96
- 97
- 98
- 99
- 100
- 101
- 102
- 103
- 104
- 105
- 106
- 107
- 108
- 109
- 110
- 111
- 112
- 113
- 114
- 115
- 116
- 117
- 118
- 119
- 120
- 121
- 122
- 123
