202110727-PERFORM-STUDENT-WORKBOOK-SCIENCE-G09-FY_Optimized

6. Tissues • cells with thin cell walls. • Collenchyma- This tissue allows easy bending in various parts of a plant (leaf, stem) without breaking. • Sclerenchyma- This tissue makes the plant hard and stiff. • Xylem and phloem are two complex tissues. They are conducting tissues and together constitute a vascular bundle. • Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres. • Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma. • Based on the functions they perform there are different types of animal tissues, such as epithelial tissue, connective tissue, muscular tissue and nervous tissue. • The covering or protective tissues in the animal body are epithelial tissues. • Blood, bone, ligament, tendons, cartilage, adipose and aerolar connective tissues are the connective tissues in the body. • Muscular tissue – Muscle tissues are of three types – Striated muscles, Smooth muscles/ Involuntary muscles/unstriated muscles and cardiac muscles. • The brain, spinal cord and nerves are all composed of the nervous tissue. The cells of this tissue are called nerve cells or neurons. Key words – parenchyma, scelerenchyma, collenchyma, neuron, blood, adipose, aerolar, ligament, bone, cartilage, xylem, phloem, meristematic tissue 38

6. Tissues Work Plan Concept Sub-Concept Practice Sheet Simulation Tissue • Definition of tissue PS-1 Meristematic tissue • Meristematic tissues • Types of meristematic PS-2 tissues PS-3 Permanent tissue • Site, structure and func- PS-4 Meristematic Tissue tion of simple permanent PS-5 Simple Permanent tissue Self-evaluation » parenchyma Sheet Tissue » collenchyma Epithelial Tissue » sclerenchyma Connective Tissue Muscular Tissue • Site, structure and func- Nervous Tissue tion of simple permanent tissue complex permanent tissue (xylem and phloem) Animal tissues • Types, site, structure and function of epithelial tissue • Types, site, structure and function of connective tissue Animal tissues • Types, site, structure and function of muscular tissue • Site, structure and func- tion of nervous tissue Worksheet for “Tissues” Evaluation with self- check or Peer check* 39

PRACTICE SHEET - 1 (PS-1) I. Fill in the blanks: 1. Intercalary meristem is present in _____. 2. ____ is found in growing tips of stem. 3. The girth of the stem has ____ meristem. 4. The cluster of cells performing the same function is called _____. 5. _________ tissue is the growing tissue in plants. II. Answer each of these questions: 1. How does meristematic tissue contribute in growth of a plant? 2. Define the term differentiation. 3. Explain the structure and function of stomata. 4. Why do the cells of intercalary tissues lack vacuoles? PRACTICE SHEET - 2 (PS-2) I. Fill in the blanks: 1. ________ forms the basic packing tissue in plants. 2. Tissue present in the husk of a coconut is ____________ 3. Stomata are enclosed by two kidney-shaped cells called ____________. 4. Epidermis of desert plants has a thick waxy coating of _________. 5. Sometimes a portion of the epithelial tissue folds inward to form _______. 6. Xylem and phloem together constitute a _________. II. Answer each of these questions: 1. Write the function of collenchyma. 2. Epidermis of desert plants is thicker compared to the coastal plants. Why? 3. How different are the epidermal cells of the root? 4. Describe distinct types of parenchyma. 5. How is phloem further divided? 6. Detail the structure of sclerenchyma. 40

PRACTICE SHEET - 3 (PS-3) I. Fill in the blanks: 1. Bone cells are embedded in a hard matrix that is composed of ______ and ________ compounds. 2. Fat storing ________ tissue is found below the skin and between internal organs 3. The covering tissues in the animal body are _____. 4. The type of tissue that forms the lining of mouth is ____. 5. The coloured part of the blood is ____. II. Answer each of these questions: 1. What are cartilages? Write its functions. 2. What are areolar tissue? Write its functions. 3. Write the location and functions and columnar epithelial cells. 4. What are ligament and tendon? How do they coordinate with bones? 5. Bones are rigid structures of our body. What is the advantage of this property to our body? PRACTICE SHEET - 4 (PS-4) I. Write one/two words for each of the following: 1. Long part of neuron. 2. Type of muscles present only in heart. 3. Proteins which contract and relax to cause movement in muscles. 4. Branched part of the neuron. II. Answer each of these questions: 1. Define nerve. 2. Write the structure, function and site of cardiac muscles. 3. Voluntary muscles move as per our wish. Why? 4. How are animals able to respond to a stimulus? 5. Differentiate between voluntary muscles, involuntary muscles and cardiac muscles with respect to their appearance. III. Draw a neat labelled diagram of a neuron. 41

PRACTICE SHEET - 5 (PS-5) 8. While doing work and running, you move your organs like hands, legs etc. which among the I. Choose the correct option: following is correct? a. Skeletal muscles contract and pull the tendon 1. Cartilage is not found in to move the bones. a. Ear b. Skeletal muscles contract and pull the ligament b. Kidney to move the bones. c. Nose c. Smooth muscles contract and pull the tendon d. Larynx to move the bones. d. Smooth muscles contract and pull the ligament 2. Sarcolemma is the membrane that covers to move the bones. a. Tendons b. Nerve fibres 9. Directions for Qns: 9 and 10: c. Muscle fibres In each of the following questions, a statement of d. Visceral fibres Assertion is given, and a corresponding statement of Reason is given just below it. Of the statements, 3. Intestine absorbs the digested food materials. given below, mark the correct answer as: What type of epithelial cells are responsible for that? a. If both Assertion and Reason are true and a. Columnar epithelium Reason is the correct explanation of Assertion b. Glandular epithelium c. Stratified squamous epithelium b. If both Assertion and Reason are true but d. Cuboidal epithelium Reason is not the correct explanation of Assertion 4. The thickening of cell wall, lignification and specialisation for mechanical function are c. If Assertion is true but Reason is false characteristic of d. If both Assertion and Reason are false a. Sclerenchyma Assertion: Smooth muscle fibres do not appear to be b. Parenchyma striated. c. Collenchyma Reason: this is due to regular alternate arrangement d. Chlorenchyma of thick and thin filaments in smooth muscle fibre. 10. Assertion: Death of companion cell results in 5. Triceps and biceps are examples of the death of its adjacent sieve tube member. a. Sphincter muscles Reason: Both are derived from the same mother b. Smooth muscles cell. c. Involuntary muscles II. Short Answer Questions: d. Voluntary muscles 1. Differentiate between epithelial and connective tissues. 6. Choose the wrong statement. 2. A student of standard IX gave the functions of a. The nature of matrix differs according to the the following cells/tissues wrongly. Correct function of the tissue. these answers and rewrite: b. Fats are stored below the skin and in between the internal orgAns: a. Muscle cells: Carry messages c. Epithelial tissues have large intercellular b. Vascular tissues in plants: Transport oxygen, spaces between them. food, hormones and waste material. d. Cells of striated muscles are multinucleate and c. Nerve cells: Contract and relax to cause unbranched. movement. d. Blood: Conduct water, mineral and organic 7. A person met with an accident in which two solutes from one part of the organism to other long bones of hand were dislocated. Which parts. among the following may be the possible reason? 42 a. Areolar tissue break b. Ligament break c. Break of skeletal muscle d. Tendon break

PRACTICE SHEET - 5 (PS-5) 3. Give one reason why a. The blood is called connective tissue. b. Muscles contain contractile proteins. c. Muscles of heart are involuntary. III. Long Answer questions: 1. What are the various types of animal tissues? Mention briefly the location and one main func- tion of each class of tissues. 2. a. What will happen if the skin epithelium is not stratified? b. What will happen if stratified squamous epithelium lines the blood vessels c. What type of layer do fishes of cold water have? Why? 43

Self-Evaluation Sheet Marks: 15 Time: 30 Mins I. Name the following: (3 Marks) 4. Describe the changes that occur in epidermis of the plant as it grows. (5 Marks) 1. Hair like projections which help in movement in the epithelial cells. 2. Chemical present in the walls of epidermis that makes them impervious to gases and water. 3. The connective tissue that acts as an insulator in the human body. II. Answer each of these questions: 1. Describe the location and structure of collenchyma. (2 Marks) 2. Justify the following statement. (2 Marks) a. Aquatic plants are not easily attacked by fungi. b. Animals of colder region have a thicker layer of subcutaneous fat. 3. Write the structure formation and function of blood cells. (3 Marks) 44

7. Diversity In Living Organisms Learning Outcomes • Classify animalia group as - Invertebrates and Vertebrates By the end of this unit, a student will be able to: • Define evolution. • Describe the body features and functioning of • Explain the 5 kingdom classification given by Ernst each phyla. Haeckel, Robert Whittaker and Carl Woese • Give examples of plants and animals belonging • List out the characteristics of Monera, Protista, to each phyla. Fungi, Plantae and Animalia. • Compare the characteristics of animals and • Classify the plantae group as - Thallophyta, plants of other phyla. Bryophyta and Pteridophyta. Concept Mapping The Hierarchy of Classification Animalia Five kingdom classification Animalia Monera Protist Fung Plantae Animalia a i Thallophyta Invertebrates - Vertebrates - Bryophyta Pteridophyta • Porifera • Pisces • Coelentrata • Amphibia • Platyhelmenthes • Reptilia • Nematoda • Aves • Annelida • Mammalia • Arthropoda • Mollusca • Echinodermata • Protochordata Key Points Characteristics of groups a) Monera- These are unicellular organisms and do 1. A large number of organisms, ranging from microscopic size to huge size exist on our planet. not have a defined nucleus or organelles. The Most life forms that we see today, have arisen by mode of nutrition of organisms in this group is an accumulation of changes in body design that either autotrophic or heterotrophic. allows the organisms, possessing them to survive b) Protista- This group includes many kinds of better. This is called evolution. unicellular eukaryotic organisms. Their mode of nutrition can be autotrophic or heterotrophic. 2. Charles Darwin first described this idea of c) Fungi- These are heterotrophic eukaryotic evolution in 1859, in his book, The Origin of organisms. They use decaying organic material as Species. food and are therefore called saprophytes. Some fungal species live in symbiotic relationship with 3. Ernst Haeckel, Robert Whittaker and Carl Woese blue-green algae (or cyanobacteria). have tried to classify all living organisms into d) Plantae- All plants are included in this group. broad five categories, called Kingdoms. They are These are multicellular eukaryotes with cell walls. Monera, Protista, Fungi, Plantae and Animalia. They are autotrophs and use chlorophyll for 45

7. Diversity In Living Organisms photosynthesis. This group is further classified ages). into various sub-groups. vii. Mollusca - These animals are bilaterally sym- i. Thallophyta- Plants that do not have well-dif- metrical. The coelomic cavity is reduced. ferentiated body design fall in this group. The viii. Echinodermata - These are spiny-skinned plants in this group are commonly called algae. These plants are predominantly aquatic. organisms. They have hard calcium carbonate ii. Bryophyta - The plant body is commonly differ- structures that they use as a skeleton. entiated to form stem and leaf-like structures. ix. Protochordata - These animals possess iii. Pteridophyta- The plant body is differentiated notochord during some stages of their lives. into roots, stem and leaves and has specialised Another sub-group of kingdom Animalia is tissue for the conduction of water and other Vertebrates/Chordates. Vertebrates are grouped into substances from one part of the plant body to five classes. another. This group is further classified, based i. Pisces- These are fish. They are exclusively on whether the seeds are naked or enclosed in aquatic animals. Their skin is covered with fruits, giving us two groups: gymnosperms and scales/ plates. They respire in water by using angiosperms. gills. The body is streamlined and a muscular e) Animalia- These include all organisms which are tail is used for movement. multicellular eukaryotes without cell walls. They ii. Amphibia- These animals are found both in are heterotrophs. This group is further classified water and on land. These animals have mucus into various sub-groups. glands in the skin and a three-chambered i. Porifera- They have pores, all over the body. heart. Respiration is through either gills or These lead to a canal system that helps in lungs. circulating water throughout the body to bring iii. Reptilia- These are terrestrial animals but can in food and oxygen. They are commonly called swim on water. These animals are cold-blood- sponges, and are mainly found in marine habi- ed, have scales and breathe through lungs. tats. iv. Aves- All birds are included in this category. ii. Coelentrata (Cnidaria) - These animals live in They lay eggs. There is an outside covering of water. There is a cavity in the body. feathers and two forelimbs are modified for iii. Platyhelminthes - They are either free-living flight. or parasitic. The body is bilaterally symmet- v. Mammals- Mammals are warm-blooded ani- rical (the left and the right halves of the body mals with four-chambered hearts. They have have the same design). The body is flattened mammary glands to produce milk to nourish dorsiventrally (from top to bottom), thus these their young. Most of the mammals give birth to animals are called flatworms. young ones. iv. Nematoda - These worms are parasitic in Keywords: Monera, Protista, Fungi, Plantae, nature. The nematode body is bilaterally sym- Animalia, Thallophyta, Bryophyta, Pteridophyta, metrical and triploblastic. The body is cylindri- Nematoda, Annelida, Platyhelminthes, cal in shape. Porifera, Coelentrata, Mollusca, Protochordata, v. Annelida - These animals are bilaterally sym- Arthropoda, Echinodermata, Pisces, Amphibia, metrical and triploblastic. They have a true Reptilia, Aves, Mammals, Triploblastic, Bilateral, body cavity. Symmetry, Evolution vi. Arthropoda - They have jointed legs (append- 46

7. Diversity In Living Organisms Work Plan SUB CONCEPT PRACTICE SIMULATION SHEET CONCEPT PS-1 Monera Protista Basis of • Characteristics of PS-2 Fungi classification hierarchic classification. PS-3 Plantae: Thallophyta Bryophyta • Evolution Pteridophyta Gymnosperms Hierarchy of • Monera Andiosperms classification • Protista Animalia:Invertebrates • Fungi Porifera • Plantae Coelenterata • Animalia Plathehelminthes Nematoda Plantae • Thallophyta Annelida • Bryophyta Arthropoda • Pteridophyta Mollusca Echinodermata • Porifera Pisces • Coelentrata Animalia Vertebrates • Platyhelminthes Amphibia Reptilia • Nematoda Aves • Annelida Mammalia • Arthropoda Animalia • Echinodermata • Mollusca • Protochordata • Pisces PS-4 • Amphibia • Reptilia • Mammalia • Aves Worksheet for “Diversity In Living Organisms” PS-5 Exercise and Self-evaluation 47

PRACTICE SHEET - 1 (PS-1) 3. Answer each of these questions. 1. What is evolution? 1. Write the names of these fungi. 2. Define the term species. Give any one example to support your answer. 3. List the characteristics of cells of group Monera. 4. How do organisms of the group Protista move? 2. Fill in the blanks. 1. The cell wall of yeast is made up of ____. 2. Blue-green algae are also called _____. 3. The scientist who gave the system of scientific naming or nomenclature is _____. PRACTICE SHEET - 2 (PS-2) I. Fill in the blanks. 1. Plants that do not have well-differentiated body design fall into the group called ________. 2. The naked embryos that are found in thallophytes, the bryophytes and the pteridophytes are called _________. 3. ___________ are also called flowering plants. 4. Liver fluke belongs to the group _______. 2. Answer in one/two word. 1. The plants of this group bear naked seeds. 2. Plants with seeds having two cotyledons. 3. The amphibians of the plant kingdom. 4. Coelenterates which live in colonies. 3. Answer each of these questions. 1. How does nutrition and respiration happen in Porifera? 2. Explain the body design differentiation in coelenterates. 48

PRACTICE SHEET - 3 (PS-3) 2. Roundworm does not have well developed digestive system. Why? 1. To which group does each of these organisms belong? 3. How does excretion occur in group mollusca? 1. Pinworm 4. What is a notochord? 2. Leeches 3. Spider 4. Balanoglossus 5. Echinus 6. Pila 2. Answer these questions. 1. Earthworms and leeches belong to the same group. Identify the group and describe their body structure. PRACTICE SHEET - 4 (PS-4) 1. Answer in one/two words. 1. Mammals which lay eggs. 2. Respiratory organ in Pisces. 3. Fishes with skeletons made entirely of cartilage. 4. A reptile that has wings like structure. 2. State whether following statements are true or false. 1. Aves are cold-blooded animals. 2. Salamander is an amphibian. 3. Fish have mucus glands in their skin. 4. Like other reptiles, crocodile has a three-chambered heart. 3. Answer these questions. 1. How is the body of birds modified for flight? 2. Why are mammals named so? 3. Detail the general characteristics of vertebrates. 49

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option: a. They treat the polluted water. b. They promote pollution. 1. The sequence of taxa in the animal kingdom is c. They act as bioindicators of pollution. a. Kingdom, phylum, class, order, family, species d. Lichens are not related with pollution. and genus b. Kingdom, phylum, class, order, family, genus 8. Sathu and Pranu observed an animal in their and species garden. Pranu called it an insect while Sathu c. Kingdom, phylum, class, family, order, species said it was an earthworm. Choose the character and genus from the following which confirms that it is an d. Phylum, kingdom, class, family, order, genus insect. and species a. Body soft and unsegmented b. Cylindrical body 2. A scientific name contains information about its c. Body rounded a. Phylum and order d. Body with jointed legs b. Class and family c. Genus and species Directions for Questions 9 and 10: d. Family and species In each of the following questions, a state- ment of Assertion is given and a corresponding 3. Who among the following is called the “Father statement of Reason is given just below it. Of of taxonomy”? the statements, given below, mark the correct a. Carolus Linnaeus answer as: b. Aristotle a. If both Assertion and Reason are true and c. John Ray Reason is the correct explanation of Assertion d. Theophrastus b. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion 4. Bryophyte acts as connecting link between: c. If Assertion is true but Reason is false a. Algae and fungi d. If both Assertion and Reason are false b. Pteridophytes and gymnosperms c. Terrestrial fungi and aquatic fungi 9. Assertion: Assertion: Fungal cells have eukary- d. Thallophyte and pteridophyte otic structure. Reason: They lack plastids. 5. Which of the following does not apply to Mollusca? 10. Assertion: Amphibians are warm blooded a. Jointed legs animals. b. Calcareous shell Reason: Amphibians never undergoes summer c. Soft unsegmented body sleep. d. Muscular foot II. Short Answer Questions: 6. True roots are absent in 1. Why are the protozoans placed in Kingdom a. Gymnosperms b. Bryophytes Protista and not in Kingdom Animalia? c. Pteridophytes d. Angiosperms 2. Classify the following organisms based on the absence/presence of true coelom 7. Which of the following is the use of lichens in (i.e, acoelomate, pseudocoelomate and coelo- case of pollution? mate) 3. Why is binomial nomenclature called so? III. Long Answer questions: 50

PRACTICE SHEET - 5 (PS-5) 1. Mention five peculiar features of class Mammalia. 2. Refer the following figures and answer the questions given: a. Identify the given figures. b. Which one belongs to 1. Platyhelminthes 2. Arthropoda 3. Annelida c. Which one has 1. Tissue level organization 2. Organ level organization d. Which one of them has poison claw? e. Which one is 1. Diploblastic - 2. Triploblastic 51

Self-Evaluation Sheet Marks: 15 Time: 30 Mins 1. Answer these questions in one sentence each. 2. Write one/two-word answer for each of the  (6 Marks) following. (3 Marks) 1. From phylum Platyhelminthes onwards, animals are categorised as triploblastic. 1. A reptile with four chambered heart. Why? 2. A mammal that gives birth to poorly 2. The presence of true body coelom is developed young ones. beneficial to the animals. Why? 3. An annelid which is used in fields to loosen 3. Why do frogs have two respiratory organs? the soil. 4. Write one similarity between Reptilia and 3. Answer these questions in 30-40 words. Amphibia. (6 Marks) 1. Write three characteristic features of group fungi. 5. Write one point of difference between cryptogams and phanerogams. 6. How are seeds of angiosperms protected? 2. Echidna and platypus are egg laying animals, yet they are grouped under mammals. Why? 52

8. Motion Learning Outcomes • Understand day-to-day activities connected with speed, average speed By the end of this unit, a student will be able to: • Understand the word meaning motion. • Distinguish between speed and velocity. • Describe motion with a referral point. • Define acceleration. • Express motion in a straight line with simple • Understand and recall the equations of motion. • Derive the equations of motion. equations and graph • Differentiate between displacement and distance. • Differentiate between uniform and non-uniform motions. Concept Map Motion Types of Change in Rate of Equations motion position motion of motion A. Uniform motion A. Distance A. Speed A. v = u + at B. Non-uniform motion B. Displacement B. Velocity B. 2as = v2-u2 C. s = ut + 1 at2 2 Key Points the rate of speed is called the velocity. • The average velocity = (initial velocity + final • When the position of any object changes with time, it is said that the object is in motion. velocity)/2 and it is expressed in metre per second. • The velocity varies with time. The rate of change • Motion of any object must be specified with a referral point. of velocity is called acceleration, it is expressed in metre per second per second (ms-2) • The total path covered by any object with • Distance travelled by any object is directly reference to time is called the distance. proportional to the time taken if the object is moving with uniform velocity. • The shortest distance measured from the Equations of motion initial to final position of the object is called 1. v = u + at its displacement. Remember magnitude of 2. s = ut + ½ at2 displacement may be 0 but not the distance 3. 2 as = v2 – u2 covered. • When an object changes its velocity due to change in magnitude and also change in direction, the • If an object covers equal distance with reference to body is said to be in uniform circular motion. equal interval of time, it is called uniform motion. • The motion of an object, moving in a circular path is an example of accelerated motion. Here, the • The ratio between the total distance travelled circumference of the path with radius ‘r’ is the and the time taken to cover this distance is called distance – displacement of the body and the time speed- the rate of motion. taken, if it is ‘t’ seconds, then the velocity of the object is equal to circumference of the path - • The unit of speed is metre per second or kilometre 2πr / t per hour. • The rate of motion is a comprehensive factor that specifies the direction in which the object moves and also the rate, with which the object moves. • The quantity that specifies both the direction and Keywords: Motion, Uniform Motion, Non-Uniform Motion, Acceleration, Velocity, Displacement, Distance, Velocity 53

8. Motion Work Plan CONCEPT COVERAGE DETAILS PRACTICE COVERAGE SHEET Description of motion • Motion along st. line PS-1 • Uniform & non-uniform motion PS-2 Speed • Speed with direction PS-3 • Displacement • Velocity PS – 4 • Acceleration PS – 5 PS – 6 Graphical • Distance – Time graph Self-evaluation representation of • Velocity – Time Graph Sheet motion • Calculation of Distance – Displacement travelled Equations of motion • E quation for velocity – time by graphical method relation • E quation for position – Time relation • E quation for position – Velocity relation • Circular motion Worksheet for “Motion” Evaluation with self- check or Peer check 54

PRACTICE SHEET - 1 (PS-1) 1. Answer each of these questions. 1. Define motion. 2. Why is the reference point or origin important to understand motion? Explain with an example. 3. Define distance. 4. Write two points of difference between distance and displacement. 5. Why is the displacement zero in many cases? 6. Define uniform motion. 7. Define non - uniform motion. PRACTICE SHEET - 2 (PS-2) 1. Answer these questions. 1. Define the terms - Speed, velocity, and acceleration. 2. Speed of a car is 50 km/hr. Convert it into m/s. 3. Give the conversion ratio for Km/hr to m/sec. 4. Define uniform acceleration with an example. 5. Derive an equation for acceleration. Mention the unit for acceleration. PRACTICE SHEET - 3 (PS-3) 1. Answer these questions. 1. Using a graph sheet, show distance – time graph for a car moving with uniform speed of 20 m s-1 for continuous 10 seconds. 2. Velocity – time graph is shown as a parallel line to the x –axis where time is represented in x-axis. What does it indicate? 3. How do you determine the distance moved by an object using velocity- time graph? 4. Arrive at the equation s = ut + ½ at2 graphically. 5. An object is dropped from rest at a height of 100 m and simultaneously, another object is dropped from rest at a height of 80 m. What is the difference in height of these 2 objects after 2 seconds, if both the objects are dropped with the same acceleration due to gravity of 10 ms-2? How does the height vary with respect to time? PRACTICE SHEET - 4 (PS-4) 1. The speed of a car goes down from 40 ms-1 to 35 ms-1 in 1/2 seconds. Find its deceleration. How far will it move further before stopping? 2. A car starts from rest and moves with an acceleration 4ms-2. Find its speed after 6 seconds and the distance travelled during that time. 3. How would you derive the equation: v2 = u2 – 2 as? 4. An object starts moving at 10 m/s with an acceleration 2m/s2. Calculate the distance travelled by it in the 3rd second. 5. A car is at a constant acceleration, passing 3 towns A, B & C, along the way. The distance between A & C is 200 Km. It passes the 3 towns at t= 0; t = 4 & t = 10 seconds, respectively. If the velocity of the car when it passes the town A is 10 m/s, find the acceleration and the distance between B & C town. 55

PRACTICE SHEET - 5 (PS-5) 1. A horse accelerates steadily from rest at 4 m/s2 for 3 sec. Find its final velocity and how far it has travelled? 2. A car starts travelling from 30m/s and moves with an acceleration 5ms-2 for a distance of 70 m. Find final velocity of the car. 3. A boy from 78.4m high cliff dropped a stone. One second later, he dropped another stone downwards with the same speed. The 2 stones reached the ground simultaneously. Find the speed of the second stone, keeping acceleration due to gravity (g) as 9.8m/s2 4. The body travelling with uniform speed has variable velocity. Give an example of such a situation. 56

PRACTICE SHEET - 6 (PS-6) I. Choose the correct option 8. A jogger leaves her house at 5:30 a.m. for jogging and returns at 6:15 am after covering 3 1. The simplest type of motion is: km. Her displacement in this time will be: a. Motion in a straight line a. 3km b. Motion in a curved path b. 2 km c. Motion in a zig zag path c. zero d. Motion in a circular path d. 9 km 2. Velocity = 9. Four jeeps A, B, C and D are moving on a levelled a. speed road. Distance Vs Time graph is given below. b. distance Which jeep is the fastest? c. time d. acceleration a. Jeep D b. Jeep A 3. A quantity has a value of – 8.0 m/s. It may be c. Jeep C the: d. Jeep B a. Speed of a particle 10. A caterpillar moves from one corner of a room b. Position of a particle to the diagonally opposite corner. If the dimen- c. Acceleration of a particle sions are 12m × 5 m, then the displacement of d. velocity of a particle. the caterpillar is: a. 13m 4. In negative acceleration, the final velocity is b. 17m a. same as the initial velocity c. 7m b. less than the initial velocity d. 144m c. double the initial velocity II. Short Answer Questions: d. Triple the initial velocity 1. An artificial satellite is moving in a circular orbit of radius 30250 km. Calculate its speed if it takes 5. Which of the following is true for Origin for 24 hours to revolve around the earth. observing the motion? 2. A ball is gently dropped from a height of 30 m. a. It is the initial point If its velocity increases uniformly at the rate b. It is the final point of 15 ms-2, with what velocity will it strike the c. It is the reference point ground? d. All of these 6. Pranu walks along a curved path and takes few rounds while walking from park to her home. Her displacement would be: a. Straight line distance to and fro. b. the total distance covered c. General direction in which she travelled d. Straight line distance between the park and home along with the direction from park to home. 7. How much distance does a bus cover when it moves 30km west and 70 km east? a. 100 km b. 40 km c. 70 km d. 30 km 57

PRACTICE SHEET - 6 (PS-6) 3. The data regarding the motion of two different objects A and B is given below. Examine them carefully and state whether the motion of the objects is uniform or non- uniform? Distance Distance Time covered by A in covered by B in 7:00 am metres metres 15 19 7:30 am 30 24 8:00 am 45 38 8:30 am 60 45 9:00 am 75 67 III. Long Answer questions: 1. Derive the relation v = u + at using the graph. 2. A truck starts from rest and moves along the x- axis with constant acceleration 6 m/s2 for 10 sec- onds. If it then continues with constant velocity, what distance will the truck cover in 16 seconds since it started from the rest? 58

Self-Evaluation Sheet Marks: 15 Time: 30 Mins 1. Write one word answer for each of these. 2. Convert the following factors: (4 Marks) a) 75 KmHr-1 to ms-1 b) 250 ms-1 to KmHr-1 a) Numerical value of a physical quantity. b) The device that shows the distance travelled by a vehicle. c) An electric appliance that shows a circular 3. Justify the statement that Displacement of motion. an object is zero, while the object actually travelled distance of 65 km. d) The rate of change of velocity. 2. Answer these questions. (1 Marks) 1. An object starts with 0 ms-1 velocity and 4. Answer these questions. (4 Marks) slowly picks up to 10 ms-1 in another 10 seconds. Calculate its acceleration. 1. A body starts from rest and is uniformly accelerated in a straight line at the rate of 5 m/s2. Calculate. a. The velocity of the body at the end of 10s b. The distance travelled by the body in the first 6s. c. The distance travelled by the body in the last 4s. d. Distance travelled during the last second. 3. Answer these questions. (6 Marks) 1. A car travelled 50 Km in 1 hour time. Subsequently it covered 60 Km in another 1 hour. Find out the average speed of the car. 59

9. Force And Laws Of Motion Learning Outcomes • Define third law of motion. • Describe the practical applications of Newton’s At the end of this lesson, students will be able to: • State the importance of friction. laws of motion • Describe balanced and unbalanced forces. • Describe the significance of the reaction forces. • Explain Galileo’s experiment. • Explain the concept of conservation of momen- • Define the first law of motion and its importance tum. in daily life. • Derive an expression on conservation of momen- • Explain the concept of inertia and mass. • Define second law of motion. tum. • Derive an expression for second law of motion. • Solve problems on the Newton’s laws of motion. • Solve problems on the first and second laws of motion. Concept Map Force and Laws of motion Friction and Forces 1st law of motion 2nd law of motion 3rd law of motion Inertia and Mass Conservation of momentum Key Points laws of motion which are also known as Newton’s laws of motion. • Force can be used to change the magnitude and velocity of an object. • Galileo deduced that objects move with a constant speed when no force acts on them. He • Forces may be balanced or unbalanced. also conducted marble experiments. • When the forces are balanced then the object • Newton studied Galileo’s idea on force and will not move. motion and presented his first law of motion. • When the object overcomes the friction in • According to first law, an object remains in a the presence of unbalanced forces then only state of rest or of uniform motion in a straight will it make the movement with the help of line unless compelled to change that state by unbalanced forces. an applied force. • The motion of the object is governed by the 60

9. Force And Laws Of Motion • All objects resist change in their state of motion because of inertia. • Inertia concepts can be seen in practical applications like when brakes have been applied on the moving vehicle, during the initial movement of the vehicle, during turning in a vehicle etc. • An object at rest tends to remain in rest: if it is moving it tends to keep moving. This property is called as inertia. • The impact force produced by moving objects depends on the mass and velocity. • The product of mass and velocity is known as momentum and is denoted by p. • Momentum has both direction and magnitude. • The rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of force known as Newton’s second law of motion. Mathematically it can be represented as F = ma. • The unit of force is kg m s-2 or newton. • When one object exerts force on the other object the second object instantaneously exerts force on the first. These force always equal in magnitude and opposite in nature. In simplified words, action and reaction forces are equal and opposite. Famously known as Newton’s third law. • The momentum of the two bodies which remain unchanged or conserved after the collison is called conservation of momentum. • In ideal collision, sum of momenta before collision and after the collision remains same. Mathematically, with usual notations it is represented as mAuA + mBuB = mAvA + mBvB Key words – friction, motion, momentum, velocity, newton’s laws, inertia and mass. 61

9. Force And Laws Of Motion Work Plan Concept Sub-Concept Practice Sheet Simulation Basic concepts of PS-1 friction and forces • Relation between motion PS-2 First law of motion First law of motion and friction Second law of PS-3 motion Second law of mo- • Balanced and unbalanced tion forces Third law of motion • Relation between forces and motion. • Galileo's experiment • Newton’s study on Galileo’s experiment • Definition of the law • Concepts of inertia and mass • Concept of acceleration and momentum • Examples relating velocity, mass and momentum • Definition of the law • Deriving mathematical expression • Problems on second law • Concepts of reaction forces • Practical examples of the reaction forces. Third Law of motion • Definition of the third law. PS-4 Conservation of momentum • Conservation of momentum • Problems Worksheet for \"Force And Laws Of Motion\" PS-5 Evaluation with self- Self-evaluation check or Peer check* Sheet 62

PRACTICE SHEET - 1 (PS-1) 1. State whether the following statements are true or false: 1. Rest is natural state of an object. 2. An object moves because of the applied unbalanced forces. 3. Define balanced and unbalanced forces. 4. Choose the correct answer. In a game of tug-of- war game, both teams are pulling the rope with same 100kg force. The force acting on the rope indicates a. Balanced forces b. Unbalanced force 5. When a cyclist stops pedalling the cycle slows down because of the a. Friction possessed by the road b. Unbalanced forces 6. What makes the object to move? 63

PRACTICE SHEET - 2 (PS-2) 1. Explain the observation of Galileo on his experiment on motion of the object. 2. State and explain the Newton’s first law of motion? 3. Define inertia and importance of inertia? 4. Choose the incorrect statement from the following. a. Feet of the human body tend to stay in rest when vehicle starts to move because of the inertia. b. Upper body stays in motion when brakes are applied because of inertia. c. Inertia is independent of mass. PRACTICE SHEET - 3 (PS-3) 1. State and explain the second law of motion. 2. State and explain momentum. 3. Derive an expression for the force with usual notations. 4. Give a few examples where second law of motion is applied in daily life. 5. A 10000 kg engine pulls of 4 containers each of 3000kg along its track. If engine exerts a force of 40000N and the track offers a friction force of 5000N, then calculate the net accelerating force; the acceleration of the engine; and the force of container 1 on 2. 6. A high speed F-1 car is moving with a high velocity of 216km/h. While taking every sharp turn, driver applies brake and to slow down it takes 2s. There are total 4 sharp turns in the circuit. Calculate the force exerted by the brakes on the F-1 car when total weight of the car with driver is 200kg. 7. Which would require a greater force to accelerate a bike of 102kg mass at 5ms-2 or a bike of 150kg mass at 3ms-2? 8. The velocity time graph of an object of 10kg moving along a straight line is given in the figure. What is the force required to stop the object? 64

PRACTICE SHEET - 4 (PS-4) 1. Define Newton’s third law of motion. 2. Justify Newton’s third law of motion with the help of a few examples. 3. A school boy of mass of 25kg jumps on a skateboard with horizontal velocity of 3ms-1. Assuming the skateboard has frictionless wheels and there are no external unbalanced forces, calculate the velocity of the school boy as the skateboard starts to move. Take the mass of the skateboard as 4kg. 4. A ball was thrown (bowled) from the bowling machine with a velocity of 40m/s. Ball weighs 160g. The weight of the bowling machine is 10kg, calculate the pullback velocity of the machine. 5. An object of mass 2 kg while travelling in a straight line hits another body of mass 5kg. Then they move together in a same straight line. If the velocity of the object is 9 ms-1 before striking another body, calculate the velocity of the combined object. Also, calculate the momentum just before the impact. 65

PRACTICE SHEET - 5 (PS-5) c. four times d. only once I. Choose the correct option: 8. The object shown below moves with 1. In balanced forces, the resultant of the applied constant velocity. Two forces are act- ing on the object. Considering negligi- force is equal to: ble friction , the resultant force will be a. Zero b. 1 a. 15 N towards left c. greater than 1 b. 15 N towards right d. cannot be defines c. 11 N towards left d. 11 N towards right 2. Which of the expression is correct to find the 9. A motorbike while taking a sharp turn tend to aF.o rFc=e?ma skid because of the sudden a. break and change of inertia b. F= ma b. displacement c. velocity c. F= ma d. acceleration m 10. Acceleration becomes half, when: a. mass is same as acceleration d. F= m b. mass is zero a c. mass is doubled d. mass is tripled 3. Rocket works on the principle of conservation of II. Short Answer Questions: a. Energy 1. Differentiate between balanced and unbalanced b. Mass forces with suitable example. c. Linear Momentum 2. A force of 3N produce an acceleration of 6m/s2 in d. velocity mass m1 and an acceleration of 24 m/s2 in mass m2 what acceleration would it give if both the 4. How much force is needed to accelerate a 4000- masses are tied together kg truck at 4 ms-2? 3. Why does a person fall forward if the driver a. 1000 N applies brake suddenly in a moving bus? Which b. 16000 N law does it apply in our daily life? c. 8000 N d. 10000 N 66 5. Which of the following has more inertia? a. 7 kg of stone b. 5 kg of carton box c. 11 kg of a suitcase d. 15 kg of a rice bag 6. Which of the following is possible in unbalanced forces? a. Stop a moving object b. Move a stationary object c. Change the shape and size of an object d. All of these 7. In the following example, try to identify the number of times the velocity of ball changes: “A football player kicks a football towards the goal. The goalkeeper of the opposite team col- lects the football and kicks it towards a player of his own team.” a. three times b. two times

PRACTICE SHEET - 5 (PS-5) III. Long Answer questions: 1. State and derive the law of conservation of momentum with a suitable diagram. 2. Observe the given diagram carefully. What is the momentum of marbles before and after collision and write the rate of change in momentum of the given marbles. Marble 1 Marble 2 Momentum before collision Momentum after collision Change in momentum Δp Rate of change in momentum 67

Self-Evaluation Sheet Marks: 15 Time: 30 Mins I. Choose the correct option: (2 Marks) IV. Solve these: (6 Marks) 1. The object moves in the presence of ______. 1. If 20 kg of metal ball falls on the metal floor from a height of 1 meter how much a. Balanced forces momentum will be transferred to the floor? Assume downward acceleration as b. Unbalanced forces 9.81ms-2. c. Frictional forces d. Gravitational forces 2. Friction acts __________ to the applied force. a. anywhere b. opposite c. in the direction d. none of the above II. Name the following: (3 Marks) 1. The unit of force 2. The rate of change of velocity is called as 3. The rate of change of momentum is called as 2. A constant force acts on object of mass 7kg for a duration of 3s. The object increases III. Give reasons in one word or in a single sen- its velocity from 3 ms-1 to 6 ms-1. If the force tence for the following statements: is applied for 5s, what would be the final (4 Marks) velocity of the object? 1. Passengers tend to remain at rest with respect to the seat until the driver applies a braking force. 2. A small mass, such as a bullet may kill a person when fired from a gun, but fast moving ping pong ball doesn’t hurt any person when it is hit. 3. 10 kg force is sufficient to pull one plastic table but, if same 5kg force is applied in both directions table will not move. 4. When the bullet is fired from the gun, the gun moves back. 68

10. Gravitation Learning Outcomes • Resolve activities connected with ‘G’ & ‘g’ • Distinguish between mass and weight. By the end of this unit, students will be able to: • Define thrust & pressure. • State the law of gravitation. • Significance of thrust and pressure in fluids. • Describe the law with practical samples. • Define buoyancy. • Define circular motion and its various terms with • Define Archimedes’ Principle and its equations. application. • Explain the importance of gravitational law. • Differentiate between ‘G’ & ‘g’. Concept Mapping Gravitation Universal law Mass and Weight Thrust and Pressure of gravitation Key Points  Buoyancy  Archimedes • It is conjectured that the apple falling down from tree and the moon getting attracted towards the principle Earth is the same force – Gravitational force.  Relative density • The object moving in a circular path is an free fall, acceleration is involved. It is due to accelerated motion that involves change in gravitational force. This acceleration is called velocity. ‘acceleration due to gravity.’ • The measure of inertia of any object is its mass. • The force that causes the acceleration and keeps • The mass of any object is a constant value and the body moving along the circular path, is acting does not change from place to place. towards the centre. • The weight of the object is the force with which it is attracted towards the Earth. • In the absence of centripetal force, the moving • The product of mass of the object and the object will move only in a straight line. acceleration due to gravity is the weight of the object and it changes from place to place as the • This straight line will be the tangent to the circle. acceleration due to gravity changes. • All the objects in the universe attract each other. • The force acting on any object, perpendicular to the surface is called thrust. This is the only force that binds the universe. • Thrust acting on unit area is called pressure. • Gravitational force is directly proportional to the • When an object is immersed in any fluid, it experiences upward thrust of the fluid. It is called product of the mass of the objects. buoyancy • Gravitational force is inversely proportional to • When the objects have lesser density than buoyancy of the liquid, then the object floats in the square of the distance between them. Hence, that liquid. larger the distance, more is the attraction between • When the objects have more density than the two bodies. buoyancy of the liquid, then the object sinks in • Earth attracts objects towards itself, is due to the that liquid. gravitational force. Gravitational force decreases • “When an object is immersed partially or fully in a with altitude. fluid, it experiences an upward thrust that is equal • Whenever an object falls towards the Earth – to the weight of the fluid displaced by it.” It is called Archimedes’ principle. 69

10. Gravitation • Mass of an object per unit volume is its density. Its unit is Kg/m3. • Density of an object determines its purity and hence it is the specific character of that object. • Relative density is the comparison of density of any object with density of water. Keywords: Gravitation, Mass, Weight, Thrust, Pressure, Density, Lactometer, Hydrometer, Relative density, Archimedes principle, Buoyancy, Fluid Wo rk Plan CONCEPT SUB CONCEPT PRACTICE SIMULATION SHEET Motion of Universal law of • Centripetal force PS-1 objects under gravitation • Universal law of gravitation the influence of gravitational Application of law of • Free fall PS-2 force of the gravitation • The value of g PS-3 Earth • Mass and weight Buoyancy: Bottle, nail & Thrust and pressure • Pressure in liquids cork in water • Buoyancy 10.4, 10.5, 10.6 • Flotation of objects on PS-4 Archimedes water principle • Archimedes principle Verifying the • Relativity density universal law of gravitation Worksheet for “Gravitation” PS-5 Evaluation with self- Self-evaluation check or Peer check* Sheet 70

PRACTICE SHEET - 1 (PS-1) 1. Give one word for the following statements. a. The force that keeps the object moving in a circular path. b. Objects in the universe attracting each other. 2. State the universal law of gravitation. 3. Give mathematical expression of universal law of gravitation. 4. What is the value of ‘G’ and who found it? 5. What is the significance of universal law of gravitation? PRACTICE SHEET - 2 (PS-2) 1. What happens to the gravitational force of attraction between 2 objects when a. Their masses are halved. b. Distance between the two objects is increased 4 times its previous value. 2. What is the force between 2 objects weighing 20 Kg mass each and placed 50 cm apart? 3. Why don’t we see objects in the universe, colliding or moving towards each other due to gravitational force? 4. Find the distance between 2 stones of mass 2 Kg each, such that gravitational force between them is 1N. PRACTICE SHEET - 3 (PS-3) 1. A ball is thrown upward with a velocity of 49m/s. Calculate a. The maximum height to which it rises. b. The total time, it takes to return to the surface of the Earth. 2. A stone is allowed to fall from the top of a tower 150m high and at the same time, another stone is projected vertically upward from the ground with a velocity of 30m/s. Calculate when and where the two stones will meet. 3. What is the nature of freely falling body in vacuum? 4. Why will a sheet of paper fall slower than the one, that is crumpled into a ball? 5. Which force is responsible for holding the solar system together? PRACTICE SHEET - 4 (PS-4) 1. Define pressure and write its SI unit. 2. Give reason for each of these statements. a. The foundation of a dam always has large surface area. b. Cutting tools are always made sharp. c. Nails have pointed ends. d. Wide wooden sleepers are kept below railway lines. 3. Find the thrust acting on the human body due to atmospheric pressure. Take the surface area of a man of middle size to be 1.5m2 and atmospheric pressure (1atm) = 1.013 X 105 Pa 4. Automobile tyres are inflated to about 30 pound/inch2 whereas bicycle tyres are inflated to 90 to 115 pound / inch2. This is almost 3 times as much pressure as that of automobile tyres. Give reason. 5. Two dams form artificial lakes of equal depth. However, one lake backs up 15 km behind the dam and the other backs up 50 km behind. What effect does the difference in length, have on the pressure on the dams? 6. Why does the air bubble increase in size on the surface of the liquid? 71

PRACTICE SHEET - 5 (PS-5) I. Choose the correct option: b. It is same as weight. c. It cannot be zero. 1. The Earth attracts a body with a force of 20N, d. all of these. with what force does that body attract the Earth? 8. At poles, the radius of the Earth is: a. 20 N a. lesser than the equator b. 10 N b. more than the equator c. N c. same as the equator d. 200 N d. zero 2. Suppose we have taken a stone to the centre of Read the following and select the correct op- the Earth, tions for 9 and 10. a. its weight is unaffected b. Its weight increases 9. Assertion: A sheet of paper fall slower than the c. its weight becomes zero one that is crumpled into a paper ball. d. its mass increases Reason: Sheet of paper has more weight than the paper ball. 3. What is the other name of Newton’s law of a. Reason is true gravitation? b. Assertion is true a. Inverse square law c. Both are true b. Law of linear momentum d. Both are false. c. Newton’s first law d. Newton’s third law. 10. Assertion: Universal gravitational constant G is the scalar quantity. 4. Which of the following statements is true? Reason: The value of G is same throughout the a. g has its maximum value at the equator. universe. b. g is same at all places on the surface of the a. Assertion is false. Earth. b. Reason is false. c. g is less at the Earth’s surface than at a height c. Assertion is true and reason is the correct above it explanation of the assertion. d. g is greater at the poles than the equator. d. Both are false. 5. The force of gravity is opposite to the direction II. Short answer questions of motion, when an object is a. thrown downwards 1. Write any three importance of Newton’s law of b. thrown upwards gravitation. c. kept on a table d. all of these 2. a. A boy drops an iron ball and a feather from the top of a tower. Which will reach first? What 6. Who among the following person feels more would be his observations? tired due to force of gravity? b. Now he puts the iron ball and the feather in a a. standing still for a longer time long jar from which air is completely evacuated. b. sitting idle for a longer time What will be observed when he inverts the jar c. sleeping long upside down? d. all of these 3. Try to touch your toes as shown in figure (a). 7. Which of the following is true for mass? Try this again when standing against a wall as a. It can be zero. shown in figure (b) Are you able to touch your toes in second case as shown in figure? If not, why? 72

PRACTICE SHEET - 5 (PS-5) III. Long answer questions 1. Draw diagram to show the position of center of gravity in each of the following objects: a. Ring b. Rectangular lamina c. Triangular lamina 2. a) Explain why a small piece of stone is not attracted towards another big piece of stone on the Earth’s surface. Also, the Earth attracts an apple. Does the apple also attract the Earth. If it does, why does the Earth not move towards the apple? b) A ship made of iron does not sink but the iron rod sinks in water, why? 73

Self-Evaluation Sheet Marks: 15 Time: 30 Mins I. Choose the most appropriate alternative for IV. Solve these. (4 Marks) each of these statements. (2 Marks) 1. A bullet fired from a gun vertically upwards 1. The mass of the body is 10 kg. Therefore its reaches a height of 160 m. weight on the Earth will be ______. a. 10 N (g = 9.8 m/s2). Calculate. b. 9.8 N i. The velocity with which the bullet was fired. c. 98 N ii. The time taken by bullet to reach that height. d. 980 N 2. The weight of body on Earth is _____. a. Same everywhere b. More at the poles and less at the equator c. More at the equator and less at the poles d. Maximum between the poles and equator II. Name the following. (3 Marks) 1. The instrument used to measure the purity of liquid. 2. The unit of pascal. 3. The upward force exerted on a body by a 2. A body of mass 80 kg and volume 0.15 m3 is fluid. immersed completely in a liquid of density 0.8 x 103 kg/m3. (g = 9.8 m/s2) III. Answer each of these questions. (6 Marks) i. Find the weight of the body. 1. How does thrust differ from pressure? ii. Find the upthrust on the body when immersed in the liquid. 2. An iron nail sinks in water but floats on mercury. Why? 3. Why can knives with sharp edges cut vegetables very easily? 74

11. Work And Energy Learning Outcomes • Explain the concept of kinetic energy. • Derive an expression for kinetic energy relating At the end of this lesson, students will be able to: • Describe the concept of work. velocity and mass. • Differentiate between the scientific work and • Explain the concept of potential energy. • Derive an expression for the potential energy for non-scientific work. • Derive an expression relating work and force. an object falling from the certain height. • Solve problems on work. • Express the law of conservation of energy with • Explain the concept of energy. • Classify the different forms of energy. examples. Concept Map Work and Energy Work Energy Work done by force Different forms of energy Problems Probploetmens toianl keinneertgicyand Key Points Law of conservation of energy • Daily activities like walking, running, cycling etc. • Pushing a pebble lying on a floor, pulling a consume lots of energy. For all these activities trolley, lifting a weight, lifting a book from the energy is supplied from food. floor is all considered as work. • For animals to do different activities energy is • If force is applied on the object and object stays required and they get energy from the food. in its position, then the total work done is zero. Similarly, for machines for doing work fuel is required. • Workdoneisaproductofforceanddisplacement. Mathematically, it is expressed as W=F s where • Work is different and activities are different. ‘F’ is the force causing a displacement of ‘s’. • Singing, solving problems, sharing thoughts, • Unit of work done is Newton meter (N m) or typing etc. are considered as work in daily life Joule. but it’s not a scientific work. • For scientific work, a force should act on an • 1 J is the amount of work done on an object object and the object must be displaced. when a force of 1 N displaces it by 1 m along the line of action of the force. 75

11. Work And Energy • Work done by the force can be positive or negative. If force acts against the direction of displacement, then it is considered as negative. • Sun is the main source of energy. • The object having capacity to do work is said to possess energy. • The unit of energy is the same as that of work, i.e. 1 Joule is the energy, required to do 1 joule of work. • Various forms of energy are kinetic energy, potential energy, heat energy, chemical energy, electrical energy and light energy. • Moving object can do work and possess energy, is called kinetic energy. Kinetic energy depends on the mass of the object and velocity. Ek=1/2 mv2. • The other form of energy is called potential energy. Potential energy of an object falling from height ‘h’ is W= mgh. • One form of energy can be converted into another form. • The sum of kinetic energy and kinetic energy of the object is always constant and that is equal to the mechanical energy. • The rate of doing work is called power(P). i.e P=w/t. • The commercial unit of energy is Kilowatt hour. 1 kWh=3.6 x 106J. • The total energy in the universe is constant. Energy cannot be created nor be destroyed it can be converted from one form to another. Famously known as the law of energy conservation. Key words – work, energy, kinetic energy, potential energy, law of conservation of energy, power. 76

11. Work And Energy Work Plan Concept Sub-Concept Practice Sheet Video/ Basic concepts of PS-1 Simulation work • Concept of scientific work • Non-scientific work Examples of kinetic Basic concept of • Work done by a constant PS-2 energy energy force • Unit of work • Concept of energy • Different forms of energy • Kinetic energy • Potential energy Law of conservation • Law of conservation of PS-3 Activity to show law of energy and basic energy of conservation of concept of power • Basic concept of power • Commercial unit of energy Worksheet for \"Work and Energy\" energy PS-4 Evaluation with self- Self-evaluation check or peer check* sheet 77

PRACTICE SHEET - 1 (PS-1) 5. An Earth mover applies a force of 5 kN on a stationary object. If the object is displaced 1. State whether the following statements are by 2 m from its position, calculate the work true or false: done. a. Attending classes from morning to evening can be considered as work. b. Climbing a tree can be considered as work. 2. Define work. 3. Choose the correct answer. A boy pulls a cart over a distance of 5m, therefore a. The work is done. b. The work is not done. 4. Define negative work. PRACTICE SHEET - 2 (PS-2) 1. Explain the concept of energy with units. 2. State and explain kinetic energy. 3. State and explain potential energy. 4.Derive an expression for energy possessed by a moving body by virtue of its motion. 5. Write an expression for a potential energy for an object at a height. 6. A school boy lifts a bag of 4 kg from the ground to the height of 1m above the ground level and puts on his shoulder. Find the work done by the boy. PRACTICE SHEET - 3 (PS-3) 1. Explain the concept of law of conservation of energy with an example. 2. Explain the concept of power with units. 3. A school building consists of 2 floors and 50 steps staircase. A boy of mass 40 kg runs upstairs in a school building, climbs up 2 floors in 20s. Each step is of 20 cm, taking g=10 m s-2, calculate the power generated by a boy. 4. A room consists of 2 tube lights each of 40W used for 6h per day. Calculate the units of energy consumed in one day by the tube lights. 5. An electric coil of 1500 W rating is used for cooking purpose for 2 hours daily for 30 days. And per unit consumed, electricity board is charging 7 rupees. What will be the total cost at the end of the month? 78

PRACTICE SHEET - 4 (PS-4) I. Choose the correct option: a. Mechanical energy to electrical energy b. Electrical energy to chemical energy 1. Work is said to be done when c. Electrical energy to mechanical energy d. Chemical energy to electrical energy a. force acts upon a body, but the body does not 8. A spring is compressed. The potential energy of move the compressed spring a. increases b. force acts upon a body and moves it in the b. decreases direction of force c. remains unchanged d. becomes zero c. force acts upon a body, but does not move it in 9. A vehicle is accelerated on a levelled road and the direction of applied force attains a velocity 4 times its initial velocity. In this process the potential energy of the car: d. no force is given a. becomes twice that of initial b. becomes 4 times of that of initial 2. Potential Energy, P.E = c. does not change mg d. becomes 16 times that of initial a. h 10. If a body is raised through height h on the sur- face of the Earth and the energy spent is E, then b. m for the same amount of energy , the body on the gh surface of the Moon will rise through the height of: c. mgh a. 12h b. 2h d. g c. 6h d. 4h mh II. Short Answer Questions: 1. Write an activity to show that a moving object 3. In equation, W=F s, if F=1 and s=1 then work can do work. Use this diagram as a base to done by force is equal to explain. a. 0 J b. 1 J 2. By giving an example from your daily life, c. 2 J explain how one form of energy is converted d. 3 J into other form. Also using the same example explain how energy is conserved. 4. If work has positive value, the body on which work has been done would 3. A person is standing by holding a heavy carton a. lose energy box and a person is lifting the same box from b. either gain or lose energy the ground. Between these two people who is c. gain energy d. neither gain nor lose energy 79 5. Energy can neither be created nor be destroyed. It can only be changed from one form to anoth- er. This is the a. Law of constant energy b. Law of gaining energy c. Law of losing energy d. Law of conservation of energy 6. If force acting on an object and displacement are in opposite directions, then the work done by the force is taken as a. positive b. negative c. neutral d. either positive or negative 7. Which type of energy conversion takes place in an electric fan?

PRACTICE SHEET - 4 (PS-4) doing work? Explain. III. Long Answer Questions: 1. Derive the expression of kinetic energy through the given diagram. 2. Justify the potential and the kinetic energy mentioned in this diagram. 80

Selff--EEvvaaluluataitoinoSnhSeheteet Marks: 15 Time: 30 Mins I. Choose the correct option: (2 Marks) IV. Solve these: (6 Marks) 1. The object stays stationary after applying 100 1. If a 40kg metal block ‘X’ falls on the floor kg force. The total work done ______. from a height of 1 meter and another metal block ‘Y’ of 20 kg falls from 3 m height a. Zero on the same floor, which metal block transfers more energy? Assume downward b. 100 N-m acceleration as 9.81ms-2. c. 100 W d. Gravitational forces 2. Work is a product of force and ____________. a. Displacement b. Power c. time II. Name the following: (3 Marks) 1. The unit of work. 2. The rate of doing work. 3. The commercial unit of energy. III. Give one word or answer in single sentence 2. Calculate the work done by an athlete of 70 for the following statements: (4 Marks) kg while increasing his speed from 5kmh-1 to 10 kmh-1. 1. Work can be positive or negative depending on the 2. The energy possessed by the moving object depends on the 3. The energy possessed by the object because of its positon is called as 4. The ability or the rate of doing work is called as 81

12. Sound Learning Outcomes At the end of this lesson, students will be able to: medium with examples. • Explain how sound is produced with examples. • Describe the concept of reflection of sound. • Describe how sound is transmitted. • Explain the concept of echo. • Explain the importance of medium for the propa- • Explain why sound damping is necessary. • Explain the practical application of multiple gation of sound. • Prove that sound needs a medium through an reflection of sound. • State the range of hearing. experiment. • Describe the application of ultrasonic sound and • Explain the characteristics of a sound wave. • Define different terms associated with sound. SONAR. • Describe how different characteristics influences • Describe how human ears are designed and how a particular sound wave. it is different from other animals . • Explain how the speed of the sound depends on Concept Map Sound Production of Sound Propagation of Sound Charcteristics of sound Echo Reflection of Sound Reverberation Key Points • When sound is produced by the vibrating source, it pushes and compresses air in front of it. This is • Sound is a form of energy which we can sense called compression region. Similarly, when the by hearing. vibrating source moves backward it creates low pressure region called rarefaction region. • Sound is produced through vibration of the source and transmits through the medium and • Sound needs a medium to travel, it can be sensed through ears. [receiver] proved with the help of Bell jar experiment. • Emitter → Medium → Receiver • Sound waves are longitudinal waves. These • Sound needs a medium for the propagation. It waves move parallel to the direction of propagation of the disturbance. may be solid, liquid or gas. • Sound is produced by the vibrating object. From • Sound waves can be described with the help of frequency, amplitude and speed. These are also the vibrating position molecules will not travel. known as characteristics of waves. Instead, it transmits the vibration to the next molecule, and the next molecule transmits the • A sound of single frequency is called as tone. The vibration to the another adjacent molecule. This mixture of different frequencies is called note. process continues in the medium till it reaches the receiver. After transmitting the vibration, the • The unwanted disturbance which is unpleasant initial molecule comes to rest. to hear is called noise. • Air is the most common medium. 82

12. Sound • The travelling speed of the sound varies depending upon the different medium. • Like many other things, sound also shows bouncing back effect called reflection of sound waves. For the reflection of sound waves smooth surface is desirable. • The multiple sound we hear due to the reflection is known as echo. The sensation of sound persists in our brain for about 0.1s. So, to hear echo, the time interval should be at least 0.1s. • The speed of the sound is about 344m/s at a 220 C in air. So, the distance between the object where reflection occurs and listener should be at least 17.2 m. • The repeated reflection of sound that results in the persistence of sound is called reverberation. • The multiple reflection effects are successfully used in megaphones, loudhailers, horns stethoscopes, cinema halls etc. • The audible range of human being is from 20 Hz to 20000 Hz. • Sound below 20 Hz frequencies are called infrasonic sound or infrasound. Sound above 20 kHz frequencies are called as ultrasonic sound. Keywords – sound, medium, characteristics of sound, sound waves, ultrasonic, human ear, range, properties of sound. 83

12. Sound Work Plan Concept Sub-Concept Practice Sheet Simulation Basic concept of PS-1 Activity to show sound • Introduction sound needs a me- Propagation of • Production of sound dium to travel sound waves • Propagation of sound • Importance of medium PS-2 Characteristics of • Science behind propaga- sound waves Characteristics of a Application of the tion sound wave properties of sound • Frequency PS-3 waves • Amplitude • Speed Reflection of sound • Definitions PS-4 • Problems • Uses of sound in different Structure of human PS-5 ear instruments Self-evaluation Sheet Worksheet for \"Sound\" Evaluation with self- check or Peer check* 84

PRACTICE SHEET - 1 (PS-1) 4. Define a medium. 5. Explain how sound propagates in any I. State whether the following statements are true or false: medium? 1. Sound is a form of energy. 6. Explain how compression and rarefactions 2. Sound is produced because of the vibrating source. are formed? 3. On which factors does quality of sound depend? 5. Choose the correct order for the following. a. Emitter → Medium →Receiver PRACTICE SHEET - 2 (PS-2) b. Medium →Emitter → Receiver c. Receiver→ Emitter→Medium 1. Explain with the help of an experiment that sound needs a medium for the 6. Choose the correct incremental order for propagation. speed of sound in different states of matter. 2. Why are sound waves called longitudinal a. liquid →solid →gas waves? b. solid → liquid →gas c. gas → liquid →solid 3. State whether the following statements are true or false. same name he hears after 10s, If the temperature is 22oC on the top of the cliff, a. Compression is the low pressure region. find the distance between the two cliffs. b. Sound reaches the listener because of the 8. Give one-word answer for the followings. actual movement of the particles. a. Speed of the sound in air is at 25oC is 4. Choose the incorrect statement from the b. The minimum distance between the source following. and reflecting surface to hear an echo is a. Sound waves are transverse waves. c. The speed of the sound in b. As the medium become denser sound travels liquids is usually above in lesser speed. 9. What is reverberation? How can it be c. Sound waves are longitudinal waves. reduced? PRACTICE SHEET - 3 (PS-3) 10. Fill in the blanks: 1. Define following terms: a. Range of hearing for human i. Frequency, ii. Amplitude, iii. Wavelength, _________. iv. Intensity. b. The sound frequencies below audible range 2. State and explain following terms with is called___________. respect to sound wave. i. Pitch ii. Tone iii. Noise iv. Note c. Frequencies higher than the audible range is called as ___________. 3. A musical instrument produces sound of 3 kHz and wave length of 40 cm. How long does it takes to travel 2.0 km? 4. How does the speed of the sound vary according to the different media? Explain with help of a few examples. 5. Explain the reflection phenomena of sound. 6. What is an echo? What is the minimum time required for an echo and why? 7. There are two cliffs. At the top of the one cliff a person shouts his name and the 85

PRACTICE SHEET - 4 (PS-4) 1. Explain how bats use ultrasonic sound to catch prey? 2. A sonar device on a submarine sends out a signal and receives an echo after 10s and the distance between the submarine and the object is 10000m.Calculate the speed of the sound in water. 3. Give 3 examples where reflection of sound concept is used. 4. Explain how defects in a metal block can be detected using ultrasound. 5. Give one-word answer for the following: a. Ultrasonic waves are made to reflect from the various parts of the heart. This technology is called _______. b. Using reflected ultrasonic waves, electric signals are generated to make images. This technique is called________. c. Sound Navigation and Ranging is also known as_________ . 6. Explain the structure of human ear, indicate its parts and explain the function of each parts through a neat labelled diagram. 86

PRACTICE SHEET - 5 (PS-5) d. All of these 8. Which of the following is true for sound travels I. Choose the correct option: 1. What does SONAR stands for? faster in summer than winter? a. As the temperature increases, speed of sound a. Sound Navigation and Reflection b. Sound Navigation and Ranging also increases c. Sound Navigation and Ranking b. In winter the temperature is low d. Sound Nomination Ranging c. As the temperature decreases, speed of sound 2. Infrasonic sound has a frequency of: a. more than 20 Hz also increases b. equal to 20 Hz d. All of these c. less than 20 Hz 9. Which of the following is true when an d. more than 20000 Hz ambulance is rushing on a road? 3. Identify the instrument shown in the following a. We hear the siren first than before we see the diagram. ambulance a. SONAR b. The speed of sound is more than the speed of b. RADAR c. Tuning fork the ambulance d. Stethoscope c. Both a and b are true 4. Which of the following part of the ear collects d. We see the ambulance first and hear the siren sound from the surroundings? a. Anvil later b. Auditory canal 10. Which of the following is kept in an auditorium c. Pinna d. Eustachian tube to prevent the excess echo? 5. Which is not the condition for hearing sound? a. Curtains a. The medium must have a large density. b. false ceilings b. There must be a vibrating body capable of c. Bright lights d. Both a and b transferring energy. c. There must be a material medium to pick up II. Short Answer Questions: 1. What is sonic boom? How does it damage build- and propagate energy. d. There must be receiver to receive the energy ings? 2. A research team sends a SONAR signal to con- and interpret it. 6. Which of the following can a slinky produce in a firm the depth of sea. They heard an echo after 10 s. Find the depth of sea water. (Speed of lab? sound in water is 1500 m/s.) a. Transverse waves 3. We can distinguish the musical notes produced b. Longitudinal waves by different musical instruments though they c. No waves have same pitch and loudness. How do you d. Both a and b think we can identify that? 7. Which of the following is the correct use of ultrasonic waves? III. Long answer questions a. Drilling holes 1. Define wavelength and amplitude of a wave. b. Detection of defects in the metals c. Ultrasonic cleaning Draw the diagram to show wavelength and am- plitude of a wave. 2. a. You and your friend are eating a crispy snack. You hear the crunchy sound of the snack but for some reason, your neighbour makes hardly any noise though he is doing the same. Why? b. In a closed box if you say hello, the sound heard will be Helloooooo………….. What does it mean? 87