202110187-APEX-STUDENT-WORKBOOK-SCIENCE-G07-PART1

(xii) Caterpillars hide in a sac of thread called cocoon. [ ] ] (xiii) Growing of silk moth and rearing silk is called apiculture. ] [ (xiv) Mulberry silk is produced by Bombyx Mori silk moth. [ 3. Fill in the blanks. [Refer to Session 3.1 ] (xv) Weavers buy silk yarn after stage. (xvi) is called ‘silk city’ of Telangana. (xvii) Killing of larvae inside the cocoon, by putting them in a steam oven is called . (xviii) The process of growing silk moth to obtain silk fibre is called . (xix) Silk thread contains and proteins. Short Answer Type Questions 4. Answer the following questions in 3-4 sentences. (i) [(Session 3.2)] How are we protected from heat and cold by wool? (ii) [(Session 3.2)] Describe the process of scouring of wool. Why is cool air passed over it? 5. Answer the following questions in 3-4 sentences. (i) [(Session 3.1)] How much silk is produced from one cocoon? (ii) [(Session 3.1)] What will happen if a cocoon is not boiled? CHAPTER 3. ANIMAL FIBRE 49

Long Answer Type Questions 6. Answer the following questions in 6-8 sentences. (i) [(Session 3.1)] Write a short note on animal fibres. AS2-Asking questions and making hypothesis Very Short Answer Type Questions 7. Answer the following questions in one sentence. [Refer to Session 3.2 ] (i) Shearing is done in early summers. Give reason for this? Short Answer Type Questions 8. Answer the following questions in 3-4 sentences. (i) [(Session 3.2)] Neha’s grandmother was making sweater for her for the winter. She want to ask her grandmother why she was making preparations for winter. What doubts she could have asked her grandmother? 9. Answer the following questions in 3-4 sentences. (i) [(Session 3.1)] Seema wants to buy a silk frock for her school annual day function. She went to market with her mother and there they found that artificial silk is much cheaper than pure silk. Seema wants to know the reason for this. Give reason. AS3-Experimentation and field investigation Short Answer Type Questions 10. Answer the following questions in 3-4 sentences. (i) [(Session 3.1)] How is silk yarn woven to fabrics? (ii) [(Session 3.1)] How is the process of reeling done? CHAPTER 3. ANIMAL FIBRE 50

Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 3.2)] If you are given a reel of wool how can you knit it? Write down the procedure of both handmade and machine made. 12. Answer the following questions in 6-8 sentences. (i) [(Session 3.1)] What are the different stages involved in the making of silk ? Write their names and describe them. AS4-Information skills and projects Short Answer Type Questions 13. Answer the following questions in 3-4 sentences. (i) [(Session 3.1)] Find out what are ’Grinages’. Long Answer Type Questions 14. Answer the following questions in 6-8 sentences. (i) [(Session 3.1)] Complete the table below Material Place where they are Uses found Silk moths Seeds Mulberry leaves AS5-Communication through drawing and model making Long Answer Type Questions 15. Answer the following questions in 6-8 sentences. (i) [(Session 3.2)] Given below are a few processes associated with making yarn from wool. Draw a flow chart by arranging them in the correct order. CHAPTER 3. ANIMAL FIBRE 51

i. Knitting ii. Weaving iii. Scouring iv. Woolen fabric v. Spinning vi. Shearing 16. Answer the following questions in 6-8 sentences. (i) [(Session 3.1)] Draw a neat and labelled diagram of the life cycle of a silkworm. AS7-Application to daily life, concern to bio diversity Short Answer Type Questions 17. Answer the following questions in 3-4 sentences. (i) [(Session 3.1)] Larvae of silkworm are killed by a process called stifling. Write your feelings about the killing for the production of silk. (ii) [(Session 3.1)] What are the health hazards for people working in wool and silk indus- try? Objective Questions AS1-Conceptual Understanding 18. Choose the correct answer. (i) Which of the following does not have concentration of tasar silk plantation? (A) Warangal (B) Karimnagar (C) Adilabad (D) Trivendrum (ii) Jamdani or ‘tie and die’ is the term given to (A) Dharmavaram silk (B) Pochampally silk (C)Kanchipuram silk (D)Banaras silk (iii) How much wool is yielded by a merino sheep in a year? CHAPTER 3. ANIMAL FIBRE 52

(A) 5 to 18 Kg (B) 3 to 15 Kg (C)10 to 25 kg (D)15 to 80 Kg (iv) Which of the following is/are a stage /stages in the life cycle of silkworm? (A) Larva (B) Pupa (C) Egg (D) All (v) Out of the following, who provides us with fibres? (A) Horse (B) Yak (C) Donkey (D) Reindeer (vi) The process that helps in storing the cocoons for a long time is (A) Reeling (B) Stifling (C) Stuffing (D) Weaving (vii) Which of the following does not have a reeling centre? (A) Hyderabad (B) Karimnagar (C) Kochi (D) Nandikotkur (viii) People who handle silk worm and silk fibres continuously suffer from problems related to skin and . (A) eyes (B) respiration (C) circulation (D) reproduction (ix) We do not get fleece from (B) Alpaca (A) Camel (D) Yak (C)Silk worm (x) The fleece of the sheep is removed from its body using a shear, generally in (A) Spring (B) Autumn (C) Summer (D) Winter CHAPTER 3. ANIMAL FIBRE 53

SESSION 1 4. MOTION AND TIME 1.1 Mind Map INTRODUCTION TO MOTION 1.2 Terminology i. Motion – An object is said to be in motion if it changes its position with respect to its surroundings in a given time. ii. Rest – An object is said to be at rest if there is no change in its position with respect to its surroundings in a given time. 1.3 Key Concepts i. Motion is a common experience in our life. Birds flying in air, buses, autos, cars, bullock carts, moving on roads, trains on railway tracks and many other objects around us are in motion. ii. An object is said to be in motion if it changes its position with respect to its surround- ings in a given time. Few examples are a moving car, a moving train etc. iii. An object is said to be at rest if there is no change in its position with respect to its surroundings in a given time. Few examples are a window, tree etc. iv. A body may be at rest with respect to one set of surroundings and at the same time be in motion with respect to another set of surroundings. SESSION 1. INTRODUCTION TO MOTION 54

1.4 Conceptual Understanding Q1. State whether the following statements are True or False. Rewrite the wrong statements (if any) correctly. [Refer to TB page 41 Q1](a,b)) (a) A body can be at rest and in motion at the same time in relation to the same set of surroundings. (b) A passenger flying in an airplane is at rest with respect to the airport and moving with respect to other passengers. A. (a) False A body can be at rest and in motion at the same time in relation to the different set of surroundings. (b) False A passenger flying in an airplane is in motion with respect to the airport and is at rest with respect to other passengers in the same plane. SESSION 1. INTRODUCTION TO MOTION 55

SESSION 2 UNIFORM AND NON-UNIFORM MOTION 2.1 Mind Map 2.2 Terminology i. Uniform motion – If a body covers equal distances in equal intervals of time, it is said to be in uniform motion. ii. Non uniform motion – If a body covers unequal distances in equal intervals of time, it is said to be in non–uniform motion. 2.3 Key Concepts i. A body is said to be in motion if its position keeps on changing with time (with respect to the observer) ii. If a body covers equal distances in equal intervals of time, it is said to be in uniform motion. SESSION 2. UNIFORM AND NON-UNIFORM MOTION 56

iii. Rotation of earth, movement of hands of a clock are few examples of uniform motion. iv. If a body covers unequal distances in equal intervals of time, it is said to be in non–uniform motion. v. A boy cycling in a crowded place, kite in the air are few examples of non–uniform motion. SESSION 2. UNIFORM AND NON-UNIFORM MOTION 57

SESSION 3 TYPES OF MOTION 3.1 Mind Map 3.2 Terminology i. Translatory motion – If all parts of a moving body move in the direction of motion then the motion is said to translatory motion. ii. Rectilinear motion – If a body in translatory motion moves along a straight line then motion is called rectilinear motion. iii. Curvilinear motion – If a body in translatory motion moves along a curved path then motion is called curvilinear motion. iv. Rotatory Motion – Rotatory motion means that, motion of all particles of a moving body follow a circular path with respect to a fixed centre or axis of rotation. v. Axis of Rotation –The straight imaginary line through all fixed points of a rotating rigid body around which all other points of the body move in circles. vi. Oscillatory motion – The ‘to’ and ‘fro’ motion of an object about a fixed point always following the same paths is called oscillatory motion. SESSION 3. TYPES OF MOTION 58

3.3 Key Concepts i. There exist different types of motion and each type is dependent on a particular situ- ation. Based on the path taken by the bodies in motion we classify motion of bodies as, Translatory motion, Rotatory motion and Oscillatory motion ii. If all parts of a moving body move in the direction of motion then the motion is said to be translatory motion. A boy riding a bicycle along a straight road is in translatory motion. iii. Translatory motion is of two types –rectilinear motion and curvilinear motion. iv. If a body in translatory motion moves along a straight line then the motion is called rectilinear motion. v. If a body in translatory motion moves along a curved path then the motion is called curvilinear motion. vi. Rotatory motion means that, motion of all particles of a moving body follow a circular path with respect to a fixed centre or axis of rotation. The motion of the wheels of a bicycle is rotatory motion vii. The to and fro motion of an object about a fixed point always following the same paths is called oscillatory motion. The movement of pendulum in a wall clock is oscillatory motion. 3.4 Conceptual Understanding Q1. State whether the following statement is True or False. Rewrite if wrong: [Refer to TB page 41 Q1](c)) The wheels of a train are in rotatory motion as well as in translatory motion, when it moves. A. True. Q2. What is common to the following? Motion of the propeller of a flying helicopter, the minute hand of a watch, the tape of a cassette recorder. [Refer to TB page 41 Q3] (a) All are examples of translatory motion. (b) All are examples of oscillatory motion. (c) All are examples of rotatory motion. (d) All are examples of periodic motion. A. (c) All are examples of rotatory motion. SESSION 3. TYPES OF MOTION 59

Q3. Which of the following is not an oscillatory motion? [Refer to TB page 41 Q4] (A) Motion of the hammer of an electric bell (B) Motion of your hands while running (C) Motion of a child on a see saw (D) Motion of a horse pulling a cart A. (D) Q4. When do you say an object is in rotatory motion? [Refer to TB page 42 Q13] A. Rotatory motion: If the motion of all particles of a moving body follow a circular path with respect to a fixed point (centre) or axis of rotation, then the body is said to be in rotatory motion. Q5. John tied a stone to a string and whirled it around. What type of motion do you find there? [Refer to TB page 41 Q2] A. The stone will be in rotatory motion as all its particles follow a circular path with respect to John’s head (a fixed point). Q6. Write the motion of different parts of a bicycle while it is in motion: [Refer to TB page 42 Q7] (a) the wheel (b) the cycle chain (c) the pedal with its arm (d) the movement of the feet pedaling (e) the movement of the rider along with the bicycle A. (a) the wheel – rotatory and translatory (b) the cycle chain – rotatory motion (c) the pedal with its arm – rotatory motion SESSION 3. TYPES OF MOTION 60

(d) the movement of the feet pedaling – rotatory motion (e) the movement of the rider along with the bicycle – translatory motion Q7. Can an object possess rotatory and translatory motion at the same time? Give an example. [Refer to TB page 42 Q14] A. Yes, a tennis ball moving along a flat plane possesses rotatory and translatory motion at the same time. Q8. In a sewing machine used by tailors, mention the type of motion of parts of the sewing machine when it runs: [Refer to TB page 42 Q16] (a) the wheel (b) the needle (c) the cloth A. In a sewing machine used by tailors, the type of motion in the following parts is: (a) the wheel –rotatory motion. (b) the needle –periodic motion (c) the cloth –translatory motion 3.5 Communication Through Drawing and Model Making Q1. Make a collection of action pictures showing living and non–living things in motion. Paste them neatly in a scrap book. Under each picture write the type of motion the picture shows. [Refer to TB page 42 Q15] A. Students’ Activity Sample Answer SESSION 3. TYPES OF MOTION 61

Translatory Circular 62 Rotatory SESSION 3. TYPES OF MOTION

SESSION 4 SLOW AND FAST MOTION, MEASUREMENT OF TIME AND SPEED 4.1 Mind Map 4.2 Terminology i. Speed –Speed of an object is the distance travelled by it in a unit of time. ii. Average Speed – Total distance travelled / Total time taken to travel the distance. iii. Speedometer –An instrument on a vehicle’s dashboard indicating its speed. Speedometer helps us know the speed of a vehicle. 4.3 Solved Examples Q1. The speed of a bus is 72 km/hr, whereas the speed of a car is 12.5 m/s. Which vehicle moves faster? SESSION 4. SLOW AND FAST MOTION, MEASUREMENT OF TIME AND S... 63

A. To compare the speed of the two vehicles, we must convert their speeds in the same units. Here, Speed of the bus = 72 km/hr Speed of car = 12.5 m/s 1 km/hr = 1000 m/3600 s = 5/18 m/s Therefore, Speed of bus = 72 km/hr = 72 x 5/18 = 20 m/s Or Speed of the car = 12.5 x 18/5 km/hr = 45 km/hr We, therefore, clearly observe that the bus is moving faster than the car. 4.4 Key Concepts i. We observe many objects in motion in our daily life. In some cases objects move slowly and in other cases they move fast. ii. The distance travelled by an object in a given interval of time can help us decide which motion is faster and which one is slower. iii. The basic unit of time is a second (s). Larger units of time are minutes (min) and hours (h). iv. The Odometer in a vehicle shows the distance travelled in kilometers and the Speedome- ter the speed of the journey in kilometres per hour. v. Average speed = Total distance travelled divided by total time taken to travel the dis- tance. vi. Speed of an object is defined as the distance travelled by it in a unit of time. vii. Unit of speed in S.I. system is meter per second (m/s). Another unit commonly used for speed is kilometer per hour (Km/h). 4.5 Conceptual Understanding Q1. Arun completed a 100 m race in 16 seconds, while Karthik finished it in 13 seconds. Who ran faster? [Refer to TB page 41 Q5] SESSION 4. SLOW AND FAST MOTION, MEASUREMENT OF TIME AND S... 64

A. To find out who is faster, we need to calculate their average speeds. Arun’s speed = Distance he ran/ Time taken = 100/16 = 6.25 m/s Karthik’s speed = Distance he ran/ Time taken = 100/13 = 7.69 m/s Karthik’s speed is greater, i.e. Karthik ran faster than Arun. Q2. I. A train runs from New Delhi to Hyderabad. It covers first distance of 420 km in 7 hrs and next distance of 360 km in 6 hrs. [Refer to TB page 42 Q6] II. Gopi takes part in a car race. He drives a distance of 70 km each in the first, second and third hours. Which of the following statements is true? a) I is an example uniform motion and II is an example of non–uniform motion. b) I is an example of non–uniform motion and II is an example of uniform motion. c) I and II are examples of uniform motion. d) I and II are examples of non–uniform motion. A. Distance covered in 1st 7 hours = 420 km Distance covered in 2nd 6 hours = 360 km Average speed in 1st 7 hours is 420 km/ 7h = 60 km/h Average speed in 2nd 6 hours is 360 km/ 6h = 60 km/h Therefore C is true. Q3. Which of the following statements is/ are correct? [Refer to TB page 42 Q8] (a) The basic unit of time is second. (b) Every object’s motion is uniform. SESSION 4. SLOW AND FAST MOTION, MEASUREMENT OF TIME AND S... 65

(c) Two cars move for 5 minutes and 2 minutes respectively. The second car is faster because it takes less time. (d) The speed of a car is expressed in km/h. A. (a) Correct. (b) Not correct. The motion of the minute’s hand of a clock is uniform. But the motion of a butterfly moving in a garden is not uniform. Not every object moves uniformly. (c) Not correct. Here another physical factor should also be defined so as to decide which car is faster. That physical factor is the distance travelled by each of the cars in the given timings. (d) Correct. Q4. What is the basic unit of speed? [Refer to TB page 42 Q9] a) km/min b) m/min c) km/h d) m/s A. The basic unit of speed is given by: (d) m/s. Q5. The correct relation between speed, distance and time is: [Refer to TB page 42 Q10] (A) speed = distance/ time (B) speed = time/ distance (C) speed = distance x time (D) distance = speed/ time A. (A) Q6. The distance between two stations is 240 km. A train takes 4 hrs to cover this distance. Calculate the speed of the train. [Refer to TB page 42 Q11] A. Distance travelled by train = 240 km Time taken = 4 h Speed of train = Distance travelled by train/ time taken= 240/4 km/h = 60 km/h SESSION 4. SLOW AND FAST MOTION, MEASUREMENT OF TIME AND S... 66

Q7. A train travels at a speed of 180 km/h. How far will it travel in 4 hours? [Refer to TB page 42 Q12] A. Speed of the train = 180 km/h Time of travel = 4 h Distance travelled by train = speed x time = 180 x 4 km = 720 km 4.6 Information Skills and Projects Q1. Gather the information about the apparatus used to measure time in olden days. [Refer to TB page 42 Q17] A. Students’ Activity Students may refer to the following links for information i. https://en.wikipedia.org/wiki/History of timekeeping devices ii. https://nrich.maths.org/6070 iii. listverse.com/2013/06/26/10–ingenious–ancient– time –keeping– devices SESSION 4. SLOW AND FAST MOTION, MEASUREMENT OF TIME AND S... 67

—— CCE Based Practice Questions —— AS1-Conceptual Understanding Very Short Answer Type Questions 1. Answer the following questions in one sentence. [Refer to Session 4.3 ] (i) Identify the types of motion in the following. Label them as rectilinear (R), curvilinear (C) or both (CR): i. Seconds hand of a watch. [ ] ii. Movement of a train on tracks. [ ] iii. Movement of a bus on a hill station road. [ ] iv. Motion of a ball on a pin board. [ ] v. Movement of tape in a tape recorder. [ ] (ii) What is the motion exhibited by a flying bird? 2. Fill in the blanks. [Refer to Session 4.3 ] (iii) Flying of kite in the air is an example for motion. (iv) A spinning top has motion. (v) Motion is always relative to the . (vi) The ‘to’ and ‘fro’ motion of an object about a fixed position is called motion. (vii) Based on the path taken by the bodies in motion, we classify motion of bodies as , and motions. 3. State true or false. [Refer to Session 4.2 ] (viii) Movement of the hour hand of a clock is an example of uniform motion. [ ] CHAPTER 4. MOTION AND TIME 68

(ix) A boy cycling in a crowded place is an example of non–uniform motion. ] [ ] ] (x) Movement of housefly is an example of uniform motion. [ (xi) Train entering into a railways station is in uniform motion. [ 4. Match the following. [(Session 4.2)] Column A Column B i. A car moving on a highway at steady a. Translatory motion speed. ii. A boy chasing a cat b. Rotatory motion iii. Rotation of a fan. c. Uniform motion iv. The pendulum of a wall clock d. Non–uniform motion v. Walking of a man in a straight line e. Oscillatory motion 5. Answer the following questions in one sentence. [Refer to Session 4.2 ] (xii) Give an example for a body which is in non–uniform motion. (xiii) How can we say that a vehicle travels in a uniform motion? CHAPTER 4. MOTION AND TIME 69

6. Match the following. Column B [(Session 4.4)] a. Girl on a swing Column A b. 5/18 m/s c. Seconds hand of a watch i. Century d. Second ii. Unit of time e. 100 years iii. 1 km/h iv. Oscillatory motion v. Uniform motion 7. Answer the following questions in one sentence. [Refer to Session 4.4 ] (xiv) Write the correct relation between speed, distance and time. (xv) How many years is one millennium? 8. Fill in the blanks. [Refer to Session 4.4 ] (xvi) The basic unit of speed is . (xvii) 1 km/h = m/s. (xviii) 10 decades = years. (xix) Speed = Distance/ . (xx) Unit of speed in S.I. system is . Short Answer Type Questions 9. Answer the following questions in 3-4 sentences. (i) [(Session 4.3)] Can an object possess translatory and rotatory motion at the same time? Give examples. (ii) [(Session 4.3)] How is a passenger flying in an airplane at rest with respect to the other passengers but moving with respect to the airport? CHAPTER 4. MOTION AND TIME 70

10. Answer the following questions in 3-4 sentences. (i) [(Session 4.4)] What are the units of speed? (ii) [(Session 4.4)] Write the units of time. Long Answer Type Questions 11. Answer the following questions in 6-8 sentences. (i) [(Session 4.2)] When do you say an object is a) at rest b) in motion c) In uniform motion d) Non Uniform motion e) Translatory motion AS2-Asking questions and making hypothesis Very Short Answer Type Questions 12. Answer the following questions in one sentence. [Refer to Session 4.1 ] (i) How can you say that motion and rest are relative? 13. Answer the following questions in one sentence. [Refer to Session 4.4 ] (i) Is estimating time important for our daily life activities? If yes give two reasons. CHAPTER 4. MOTION AND TIME 71

Short Answer Type Questions 14. Answer the following questions in 3-4 sentences. (i) [(Session 4.2)] Earth rotates on its own axis. Why can’t we feel Earth’s rotation? Give reason. 15. Answer the following questions in 3-4 sentences. (i) [(Session 4.4)] Rani’s brother gave her a stop watch and asked her to count the time while he was running. What possible doubts Rani asked her brother about stop watch? AS3-Experimentation and field investigation Short Answer Type Questions 16. Answer the following questions in 3-4 sentences. (i) [(Session 4.3)] What are the observations which will tell you that a tennis ball has both rotatory and translatory motion? Long Answer Type Questions 17. Answer the following questions in 6-8 sentences. (i) [(Session 4.2)] What procedure would you apply to prove that a pendulum covers equal distances in equal intervals of time and is in uniform motion? AS4-Information skills and projects Short Answer Type Questions 18. Answer the following questions in 3-4 sentences. (i) [(Session 4.4)] A bus covers a distance from A to B at 40 km/h and while returning it travels at 50 km/h. Calculate the average speed out of the given information. Long Answer Type Questions 19. Answer the following questions in 6-8 sentences. (i) [(Session 4.4)] Based on the given information answer the following questions. The odometer of a car reads 57321.0 km when the clock shows the time 8:30 AM. What is the distance moved by the car, if at 08:50 AM, the odometer reading has changed to 57336.0 km? Calculate the speed of the car in km/min during this time. Express the speed in km/h also. CHAPTER 4. MOTION AND TIME 72

(ii) [(Session 4.4)] Given below is distance covered by car in given time. Answer the questions that follows based on this information. Q1. A car covers a distance of 100 km in 5 hours, calculate its speed. Q2. A car covers 20 km in the first hour and covers 30 km in the last 4 hours. Find its average speed. AS5-Communication through drawing and model making Long Answer Type Questions 20. Answer the following questions in 6-8 sentences. (i) [(Session 4.3)] Draw an example for each to show: i. Translatory motion ii. Rotatory motion iii. Oscillatory motion AS6-Appreciation and aesthetic sense, Values Short Answer Type Questions 21. Answer the following questions in 3-4 sentences. (i) [(Session 4.4)] In today’s fast moving environment, people use cab services to move from one place to another. How would you appreciate the calculation of the total price of the travel? Long Answer Type Questions 22. Answer the following questions in 6-8 sentences. (i) [(Session 4.4)] What are the different units of time? How do you appreciate the need for these different units of time? Give three examples from your daily life. AS7-Application to daily life, concern to bio diversity Short Answer Type Questions 23. Answer the following questions in 3-4 sentences. CHAPTER 4. MOTION AND TIME 73

(i) [(Session 4.3)] Observe the following incidents which we can see commonly in our surroundings. Write down the type of motion you observe in them. i. A girl swinging on a jhula ii. A grandfather’s old pendulum clock iii. A pottery wheel iv. A moving ball 24. Answer the following questions in 3-4 sentences. (i) [(Session 4.4)] How can we decide which object which one is faster and which one is slow? Give any four incidents in our daily routine where we talk about time. Objective Questions AS1-Conceptual Understanding 25. Choose the correct answer. (i) The total distance travelled divided by total time taken to travel the distance is called (A) Average speed (B) Average distance (C)Average time (D)Average motion (ii) In the sewing machine your mother uses for stitching, the type of motion in the needle is: (A) Translatory motion (B) Rotatory motion (C)Circulatory motion (D)Oscillatory motion / periodic motion (iii) The basic unit to measure time using clocks, watches and stop clocks is: (A) Millisecond (B) Seconds (C) Minutes (D) Hours (iv) The instrument that records instantaneous speed of a vehicle is (A) Speedometer (B) Thermometer (C) Calorimeter (D) Seismometer CHAPTER 4. MOTION AND TIME 74

(v) The movement of pendulum in a wall clock is known as (A) Oscillatory motion (B) Rectilinear motion (C)Curvilinear motion (D)Rotatory motion (vi) The unit of speed in the S.I. system is (B) meter per minute (A) meter per second (D)meter per day (C)meter per hour (vii) A car has travelled 60 km in 1 hour. What is the average speed travelled by the car? (A) 60 km/h (B) 70 km/h (C)80 km/h (D)90 km/h (viii) How many years make a decade? (B) 10 years (A) 5 years (D)20 years (C)15 years (ix) Which among the following is translatory motion? (A) A car travelling in a straight line (B) Motion of blades of a ceiling fan (C)Movement of fan in air cooler (D)Movement of hands of a clock (x) To calculate total distance covered, we calculate by using the formula (A) Distance = Speed / Time (B) Distance = Speed X Time (C)Distance = Time / Speed (D)Distance = Time + Speed CHAPTER 4. MOTION AND TIME 75

5. TEMPERATURE AND ITS MEASUREMENT SESSION 1 INTRODUCTION TO TEMPERATURE AND HEAT 1.1 Mind Map 1.2 Terminology i. Temperature – Temperature is a measure of the degree of hotness or coldness of an object. ii. Heat energy –Heat energy is defined as the amount of energy that has to be trans- ferred to or from one unit of mass (kilogram) or amount of substance (mole) to change the system temperature by one degree. SESSION 1. INTRODUCTION TO TEMPERATURE AND HEAT 76

1.3 Key Concepts i. We come across many things that are hot and cold in our day to day life such as tea is hot and ice cream is cold. ii. We can measure degree of hotness and coldness in terms of temperature. iii. Temperature is a measurement to express the degree of hotness or coldness of an object or a body. iv. Hot and cold temperature is due to presence and absence of heat which is a form of energy. v. There is a continuous flow of heat energy from one object to other or from object to surroundings. vi. The flow of heat takes place from a body at higher temperature to body at lower temperature. vii. Heat can be converted to other forms of energy and other forms of energies can be converted to heat. 1.4 Conceptual Understanding Q1. During winter mornings, why do people stand in the sun? Explain. [Refer to TB page 51 Q4] A. i. During winter mornings we feel cold inside the house. ii. If we come out and stand in the sun, we feel warm. iii. The heat from the sun falls on our body, and a part of it is absorbed by the skin and the temperature increases. So we feel warm and comfortable. Q2. After walking some distance on a hot summer day, why do we prefer to go into shade? [Refer to TB page 51 Q5] A. i. After walking some distance on a hot summer day, we prefer to go into the shade because the shade will be at a lower temperature than the direct heat of sun. ii. When we take shelter in shade the body temperature becomes lowered a little and we feel comfortable. Q3. Heat energy is converted into other forms of energy. Give some examples. [Refer to TB page 51 Q10] SESSION 1. INTRODUCTION TO TEMPERATURE AND HEAT 77

A. Heat energy can be converted into other forms of energy. Examples: i. When the filament of an electric bulb is heated by electrical energy to a high tem- perature, it emits light. Here, heat energy is converted into light energy. ii. In a steam engine the heat energy converts water into steam and the energy of the steam is converted into mechanical energy. iii. In a steam locomotive, the heat energy released from burning coal produces steam and the steam makes the locomotive run along the railway track. Thus heat energy is converted into motion, that is kinetic energy. iv. Heat energy obtained by burning coal is used to generate electrical energy in ther- mal power stations. Q4. Fill in the blank: [Refer to TB page 52 Q13.C] (c) Heat energy is transferred from to . A. (c) Heat energy is transferred from warmer objects to colder ones. 1.5 Asking Questions and Making Hypothesis Q1. Prathima said, “Heat is a form of energy”. How do you support her? [Refer to TB page 51 Q11] A. Let us consider an example to explain that heat is a form of energy. i. When water is boiling in a closed vessel, the lid keeps moving up and down. Some- times the lid is thrown away too. We need energy to make this happen. ii. This energy comes from the heated water. The water gets the energy from the heat of the fire. iii. Thus, heat is a form of energy. Heat is defined as the energy which makes an object appear hot or cold. iv. Heat energy can be transferred from an object of higher temperature to one at lower temperature. v. It can also be converted to other forms of energy like electrical energy, mechanical energy, etc. and vice versa. For example, SESSION 1. INTRODUCTION TO TEMPERATURE AND HEAT 78

• If we use electrical heater to heat water, electrical energy is converted to heat. • If we use a gas stove or kerosene stove to heat water, chemical energy is converted into heat energy. In the above examples other forms of energy are converted into heat energy. In the same way, the heat energy produced in an electric bulb is converted into light energy. So we can say, heat is a form of energy just like electrical energy, light energy or me- chanical energy and can be converted into other forms of energy. SESSION 1. INTRODUCTION TO TEMPERATURE AND HEAT 79

SESSION 2 MEASURING TEMPERATURE 2.1 Mind Map 2.2 Terminology i. Thermometer –An instrument for measuring and indicating temperature. ii. Fahrenheit scale – Fahrenheit (symbol °F) is a temperature scale in which 32° repre- sents the melting points of ice as the lower fixed point and 212° represents the boiling point of pure water as upper fixed point under standard atmosphere pressure. iii. Celsius scale –A scale of temperature in which 0° represents the melting point of ice as lower fixed point and 100° represents the boiling point of water as upper fixed point. iv. Expansion –The action of becoming larger or more extensive. 2.3 Key Concepts i. Heat and temperature, although different concepts but are closely interrelated. SESSION 2. MEASURING TEMPERATURE 80

ii. A body’s heat energy is measured as temperature. iii. Temperature of a body decides its ability to take up or loose heat. iv. The temperature of a body can be measured accurately using an instrument called thermometer. v. Thermometers work on the principle that heat cause expansion. vi. Mercury or alcohol are used as thermometer liquids. These liquid expands on heating. vii. In a thermometer, the temperature of melting ice is taken as the lower fixed point and the temperature of boiling water is taken as the upper fixed point. viii. Unit of measuring temperature of a body is degree. ix. In a Celsius Thermometer the distance between the two points is divided into 100 equal parts. Each division is called a degree and represents 1°C. 1°C again further divided into 10 small divisions. It can be read as 1/10 = 0.1°C. x. In Celsius scale of temperature, the lower fixed point is 0° and the upper fixed point is 100°. There are hundred equal divisions between the L.F.P. and the U.F.P. xi. 79°C is read as 79 degrees Celsius (or) centigrade. xii. In Fahrenheit thermometer, the L.F.P. is 32° and the U.F.P. is 212°. There are 180 equal divisions between the L.F.P and the U.F.P. xiii. 45°F is read as 45 degrees Fahrenheit. 2.4 Conceptual Understanding Q1. Why do we use mercury in thermometers? Can water be used instead of mercury? What are the problems in using it? [Refer to TB page 51 Q2] A. The reasons for using mercury in the thermometers: i. Mercury expands uniformly. ii. It is an opaque shining liquid. iii. It does not stick to the sides of the capillary tube. iv. It is a good conductor of heat. v. It is easily available in a pure state. No, water cannot be used instead of mercury in thermometers.This is because i. In cold conditions the water would freeze in the tube making the measurement un- readable or the complete opposite when it gets very hot the water would evaporate in the tube. SESSION 2. MEASURING TEMPERATURE 81

ii. A thermometer works through heat convection. Mercury has the perfect properties to fit the convection cycle and still give an accurate measurement on temperature. iii. Moreover water sticks to the glass sides. So, mercury is used as thermometric liquid because of its high density and other properties. Q2. Temperature of Srinagar (J & K) is –4°C and that of Paderu (AP) is 3°C. Which of them has greater temperature? What is the difference between the temperatures of the two places? [Refer to TB page 51 Q3] A. The temperature of Paderu is greater than the temperature of Srinagar because 3 is greater –4. The difference in temperatures is = 3 °C - (-4 °C) = 3 °C + 4 °C = 7 °C. Q3. Fill in the blanks: [Refer to TB page 52 Q13](b), (d)) (b) At room temperature mercury is in state. (d) –7°C temperature is than 0°C temperature. A. (b) At room temperature mercury is in liquid state. (d) –7°C temperature is lower than 0°C temperature. 2.5 Experimentation and Field Investigation Q1. Use a thermometer and record the temperature in your school daily at mid–day meals time in the following table. Record temperature for a month. [Refer to TB page 52 Q15] Date Temperature SESSION 2. MEASURING TEMPERATURE 82

On which day was the temperature highest? What could be the reason? On which day was the temperature lowest? What could be the reason? What was the average temperature during the month? (Hint: Find this by adding all the temperatures and dividing it by the number of days of the month.) A. Students’ Activity. SESSION 2. MEASURING TEMPERATURE 83

SESSION 3 CLINICAL AND LABORATORY THERMOMETERS 3.1 Mind Map 3.2 Terminology i. Clinical thermometer –A small medical thermometer with a short but finely calibrated range, for taking a person’s temperature. ii. Digital thermometer –An instrument that measures the temperature of something or someone in an LCD. iii. Laboratory thermometer – A laboratory thermometer is a tool used in laboratories to measure temperature with a high level of accuracy. 3.3 Key Concepts i. Thermometers are the instrument used for measuring temperature of a body. ii. A variety of thermometers are available in the market for different purposes. These are clinical thermometer, digital thermometer, six’s maximum–minimum thermometer, laboratory thermometer etc. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 84

iii. Clinical thermometers are used by doctors to measure temperature of human body. It contains mercury as a thermometer liquid. There is a kink in the capillary tube of a clinical thermometer above the bulb. This prevents mercury level from falling on its own. iv. Digital thermometers are thermometers that do not use mercury as thermometric liq- uid v. Digital thermometers are being used in clinics now a days as they are much safer. vi. Laboratory thermometers are used to measure temperatures of objects other than the human body. It is used in laboratories and research centres. vii. A day’s minimum and maximum temperature is recorded using Six’s maximum–minimum thermometer. viii. Mercury and alcohol are used as thermometric liquids in maximum–minimum ther- mometers. 3.4 Conceptual Understanding Q1. The body temperature of Srinath is 99°F. Is he suffering from fever? If so, why? [Refer to TB page 51 Q1] A. i. The body temperature of Srinath is 99°F. The normal temperature of a healthy person is 98.4°F. ii. But there will be a little variation of body temperature from one person to the other. iii. So, there is nothing wrong with Srinath. He is perfectly healthy . Q2. Swathi kept a laboratory thermometer in hot water for some time and took it out to read the temperature. Rani said it was a wrong way of measuring temperature. Do you agree with Rani? Explain your answer. [Refer to TB page 51 Q8] A. i. One of the precautions to be taken while measuring temperatures of bodies is the bulb should be surrounded from all sides by the substance whose temperature is to be measured. ii. When Swathi took the thermometer out, a part of mercury will fall back into the bulb due to low temperature of surroundings. iii. So we do not get the accurate measure of temperature of the substance we are measuring. So what Rani said is correct. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 85

Q3. Jyothi was prepared to measure the temperature of hot water with a clinical thermome- ter. Is it right or wrong? Why? [Refer to TB page 51 Q7] A. i. Jyothi is wrong in using a clinical thermometer to measure the temperature of hot water. ii. The range of a clinical thermometer is 35°C to 45°C. But the temperature of hot water could certainly be greater than 45°C. iii. So, if a clinical thermometer is used to measure the temperature of hot water, the mercury will expand beyond the 45°C mark and as there is no space above that, the mercury may break the capillary tube and the thermometer gets destroyed. iv. So Jyothi cannot measure the temperature of hot water using a clinical thermome- ter. Q4. Why do we jerk a clinical thermometer before we measure body temperature? [Refer to TB page 51 Q9] A. i. Before we measure body temperature we jerk a clinical thermometer. ii. The level of mercury in the capillary of the thermometer should be below 35°C. iii. In order to bring mercury into the bulb we jerk the thermometer. Otherwise the level of thermometer which was already at a certain reading may give us a wrong measurement. Q5. Why is a clinical thermometer not used to measure the temperature of air? [Refer to TB page 51 Q12] A. i. The temperature range of a clinical thermometer is 35 °C to 45 °C. During winter, the temperature of many places in our state falls below 35 °C. ii. Similarly in summer the temperature of certain places in our state would be higher than 45 °C. iii. So the capillary tube may break if we measure temperature of air which go beyond the range of a clinical thermometer and it will be destroyed. iv. So, we should not use a clinical thermometer to measure the temperature of air. Q6. Fill in the blank: [Refer to TB page 52 Q13](a)) (a) Doctor uses thermometer to measure the human body temperature. A. (a) Doctor uses clinical thermometer to measure the human body temperature. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 86

Q7. Match the following: [Refer to TB page 52 Q14] A. 3.5 Asking Questions and Making Hypothesis Q1. Srikanth takes a sip of cold drink and feels the chill. Guess what its temperature is? Try to measure it. [Refer to TB page 51 Q6] A. i. The temperature of cold drink will be a little above 0°C, which is the melting point of ice. ii. To measure the temperature of cold drink we can use a laboratory thermometer on which Celsius scale is marked. 3.6 Experimentation and Field Investigation Q1. Measure the body temperature between fingers, under the tongue, armpit, folded hands, folded leg etc. Is it the same? Does the body temperature remain the same after jumping ten times? Why? [Refer to TB page 52 Q18] A. i. The body temperature may vary slightly from one part to the other. The correct place to measure the accurate body temperature is under the tongue. ii. But due to the fear that the children may bite and break the bulb of thermometer it is placed under the armpit to record the temperature of children. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 87

iii. If we jump ten times and note the temperature of the body, it shows a slight in- crease. iv. The reason is that, some energy is released in the form of heat to make us jump and so our body gets a little warmed up. Hence, we find a slight increase in our body temperature. Q2. Measure the temperature of water in normal conditions. If you add the following sub- stance to the water, do you find any difference in temperature? Predict and verify. [Refer to TB page 53 Q20] Water Water (100 ml Prediction Temperature temperature each time) Decrease of the solution mixed with in Celsius two table immediately spoonful of after mixing each the substance Glucose Washing powder Baking soda Sugar Common salt Do you find any change in temperature before and immediately after mixing the above substances in water? If yes, what could be the reason? A. Students’ Activity. (Addition of some substances may lower or increase the temperature of water due to release or loss of energy) SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 88

3.7 Information Skills and Projects Q1. Collect information from hospital/health centre about the precautions to be taken while reading temperature with a clinical thermometer. [Refer to TB page 52 Q19] A. i. Thermometer should be washed before and after use, preferably with an antiseptic solution. ii. Ensure that before use the mercury level is below 35 degree Celsius. iii. Read the thermometer keeping the level of mercury along the line of sight. iv. Handle the thermometer with care. Avoid keeping it in the sun or near a flame. v. Do not hold the thermometer by the bulb while reading it. 3.8 Communication Through Drawing and Model Making Q1. Draw the diagram of a clinical thermometer and label its parts. What is the use of the kink in a clinical thermometer? [Refer to TB page 52 Q16] A. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 89

Use of kink/bend : The kink prevents the level of mercury from falling on its own. So, it enables us to take the exact reading of temperature of the body, even after it is taken out. Q2. Draw the diagram of a laboratory thermometer and label its parts. How does it differ from a clinical thermometer? [Refer to TB page 52 Q17] A. Differences between a laboratory thermometer and clinical thermometer: Laboratory thermometer Clinical thermometer 1. There is no 1. There is a kink in the kink in the capillary near capillary near the mercury the mercury bulb. bulb. 2. Used to 2. Used to measure measure temperatures temperatures of substances of sick in the persons in laboratory. the hospitals or at home. SESSION 3. CLINICAL AND LABORATORY THERMOMETERS 90

3. In a Celsius 3. The range of thermometer temperature the range of is 35°C to temperatures 45°C. it can measure is from 0°C to 100°C. —— CCE Based Practice Questions —— AS1-Conceptual Understanding energy is Very Short Answer Type Questions 1. Fill in the blanks. [Refer to Session 5.1 ] (i) If we use electric water heater to heat water, converted into heat. (ii) In solar heaters, energy is converted to heat energy. (iii) Heat energy always transfers from to . (iv) is a measure of degree of hotness or coldness of an object. CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 91

2. Match the following. Column B [(Session 5.2)] Column A a. 37◦C b. 100◦C i. State of Hg at room temperature c. 0◦C d. Liquid ii. Normal temperature of human body e. A form of energy iii. Heat iv. Boiling point of water v. Melting point of water 3. Answer the following questions in one sentence. [Refer to Session 5.2 ] (v) What liquids are used as thermometer liquids? (vi) Expand MMT. 4. Fill in the blanks. [Refer to Session 5.2 ] (vii) The temperature of a human body is measured by a thermometer. (viii) The first thermometer was invented by . (ix) The temperatures of a day are measured by thermometer. (x) The liquid used in Six’s maximum minimum thermometer is . (xi) is used to prevent the mercury from falling down on its own in a clinical thermometer. CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 92

5. Answer the following questions in one sentence. [Refer to Session 5.3 ] (xii) What do you do to protect yourself from cold? (xiii) How do you get hot water in winter? (xiv) Why do we feel cold when we bathe with cold water? (xv) Give two examples of conversion of energy from one form to the other. 6. Fill in the blanks. [Refer to Session 5.3 ] (xvi) thermometer is mainly meant for infants. Short Answer Type Questions 7. Answer the following questions in 3-4 sentences. (i) [(Session 5.1)] What are the different types of clothes you wear in different seasons? 8. Answer the following questions in 3-4 sentences. (i) [(Session 5.2)] The body temperature of Srinath is 99◦F. Is he suffering from fever? (ii) [(Session 5.2)] Temperature of Srinagar is −4◦C and in Paderu, it is 3◦C . Which place has greater temperature? What is the difference in temperature of both the places? (iii) [(Session 5.2)] Why is alcohol also preferable to use in thermometers? 9. Answer the following questions in 3-4 sentences. (i) [(Session 5.3)] Write a note on clinical thermometer. (ii) [(Session 5.3)] We should not expose thermometer to hot sun or flame. Why? What happens? CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 93

Long Answer Type Questions 10. Answer the following questions in 6-8 sentences. (i) [(Session 5.2)] Why do we use mercury in thermometers? Can water be used instead of mercury? What are the problems in using it? 11. Answer the following questions in 6-8 sentences. (i) [(Session 5.3)] State similarities and differences between the laboratory thermometer and the clinical thermometer. AS2-Asking questions and making hypothesis Short Answer Type Questions 12. Answer the following questions in 3-4 sentences. (i) [(Session 5.1)] Rupali and Shalmali are out for shopping in their summer vacation. Rupali has worn white cotton saree while Shalmali has worn a dark blue silk saree. Who do you think would feel more hot? Give two points supporting your answer. (ii) [(Session 5.1)] Raman covered the mercury thermometer with a coloured paper. He had doubts whether the thermometer acts like an alcohol thermometer. What ques- tions would he ask to clarify his doubts ? 13. Answer the following questions in 3-4 sentences. (i) [(Session 5.2)] Abhay and Aryan want to study the details of the environment when it snows. Abhay says, using a mercury thermometer will be helpful but Aryan insists on thermometer with alcohol used as liquid in it. Whom would you support? Give two points to support your answer. (ii) [(Session 5.2)] If we keep mercury thermometer in deep freezer will it work? Give reason. (iii) [(Session 5.2)] Melting point of ice and boiling point of water are used to create a scale in the thermometer. What questions would you ask to know how the scale is created? AS3-Experimentation and field investigation Very Short Answer Type Questions 14. Answer the following questions in one sentence. [Refer to Session 5.2 ] CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 94

(i) Why are we advised not to use laboratory thermometer to measure body tempera- tures? Short Answer Type Questions 15. Answer the following questions in 3-4 sentences. (i) [(Session 5.1)] Give 3 examples to show that heat flows from higher temperature to lower temperature. 16. Answer the following questions in 3-4 sentences. (i) [(Session 5.3)] What is the procedure to be followed for measuring body temperature? What are the precautions while taking the reading? AS4-Information skills and projects Short Answer Type Questions 17. Answer the following questions in 3-4 sentences. (i) [(Session 5.3)] Complete the information about the different types of thermometers. Name of the Uses thermometer Clinical Thermistor Laboratory Digital Long Answer Type Questions 18. Answer the following questions in 6-8 sentences. (i) [(Session 5.3)] Record the temperature of at different places in your school like your class room, play ground, library, staff room in the morning, afternoon and evening? Do you see a change in the temperature in the different places and in different times. CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 95

Morning Afternoon Evening Classroom Play ground Library Staff room (ii) [(Session 5.3)] Find out various scales of thermometer. AS5-Communication through drawing and model making Long Answer Type Questions 19. Answer the following questions in 6-8 sentences. (i) [(Session 5.2)] Draw a diagram to show expansion of liquid due to heat. 20. Answer the following questions in 6-8 sentences. (i) [(Session 5.3)] Draw the diagram of a clinical thermometer and label its parts. (ii) [(Session 5.3)] Draw the diagram of Six’s maximum and minimum thermometer? AS6-Appreciation and aesthetic sense, Values Long Answer Type Questions 21. Answer the following questions in 6-8 sentences. (i) [(Session 5.3)] Appreciate the use of thermometer in various fields. AS7-Application to daily life, concern to bio diversity Short Answer Type Questions 22. Answer the following questions in 3-4 sentences. (i) [(Session 5.1)] Discuss why wearing of more layer of clothes during winter keep us warmer than wearing single layered clothes. (ii) [(Session 5.1)] In places of hot climate, it is advised to paint the outer walls of houses white. Explain CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 96

Objective Questions AS1-Conceptual Understanding 23. Choose the correct answer. (i) When water is boiling and being converted into water vapour, the volume of the water vapour (A) Decreases (B) Increases (C)Remains the same (D)Cannot be predicted (ii) Where does the conversion of heat energy to electrical energy take place? (A) Solar power station (B) Nuclear power station (C)Thermal power station (D)Magnetic power station (iii) In a gas stove, which form of energy is converted in to heat? (A) Chemical energy (B) Thermal energy (C)Food energy (D)Electrical energy (iv) The melting point of ice occurs at (B) 0 degree (A) Room temperature (D)33 degrees (C)100 degrees (v) The first thermometer was invented in (B) 1359 (A) 1953 (D) 1539 (C) 1593 (vi) The normal temperature of the human body measured by clinical thermometer is (A) 95.8◦F (B) 98.6◦F (C) 96.8◦ F (D) 95.6◦ F CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 97

(vii) Which thermometer should be used to measure the temperature of the human body? (A) Digital thermometer (B) Thermistor thermometer (C)Laboratory thermometer (D)Maximum minimum thermometer (viii) Apart from mercury which other liquid is used in thermometers? (A) Water (B) Petrol (C) Alcohol (D) Milk (ix) Generally how long does a thermometer take to sense your body temperature? (A) 1 second (B) 1 minute (C)1 hour (D)1 day (x) What prevents the mercury from falling of its own in a thermometer? (A) Bulb (B) Kink (C) Capillary (D) Jerk CHAPTER 5. TEMPERATURE AND ITS MEASUREMENT 98