CBSE Class 7 Science Motion And Time Worksheet

1.Three types of motion are-
(A) Circular, Rotational and Vibratory.
(B) Rectilinear, Circular and Periodic.
(C) Uniform, Periodic and Circular.
(D) Non uniform, Periodic and Temporary.

2.What is speed?

3.Define non-uniform motion?

4.Which devices are used to measure time intervals?

5.What is a bob?

6.What is a periodic motion?

7.Define time period of a simple pendulum?

8.What are quartz clocks?

9.What is the use of odometer in a vehicle?

10.What is the use of speedometer in a vehicle?

11.Basic standard unit of time is a-
(A) Second.
(B) Hour.
(C) Minute.
(D) All of these.

12.Quartz clocks-
(A) Have an electric circuit with one or more cells.
(B) Show more accurate time than the clocks available earlier.
(C) Have a pendulum.
(D) Are more accurate because they have an electric circuit with one or more cells.

13.Slower moving vehicle will have-
(A) Higher speed.
(B) Slower speed.
(C) Equal speed.
(D) More distance.

14.The time period of a simple pendulum does not change, if the displacement of bob is slightly changed.
(A) The statement is not always true.
(B) The statement is always true.
(C) The statement is sometimes true.
(D) The statement is absolutely wrong.

15.Time period is measured by-

(A) Releasing the bob from its extreme position and not pushing it.
(B) Counting the oscillations when the bob is on the extreme.
(C) Noting the time taken by the bob to complete about 20 oscillations and dividing it by the number of oscillations.
(D) All of these.

16.Speed can be defined as the-
(A) Distance travelled in unit time.
(B) Distance travelled.
(C) Distance travelled by light.
(D) None of these.

17.Time period is defined as-
(A) The time taken to complete one revolution.
(B) The time taken to go from one extreme to the other.
(C) The time taken to return to mean position from the extreme on one side only.
(D) All of these.

18.Average speed is the total distance covered-
(A) Divided by the distance travelled in one hour.
(B) Multiplied by the total time taken.
(C) Divided by the total time taken.
(D) All of these.

19.An oscillation is said to be complete when-
(A) The bob of pendulum starts from its mean position.
(B) The bob of pendulum moves to extreme on one side and goes to the extreme on the other side.
(C) The bob of pendulum returns to its original mean position.
(D) The bob of the pendulum starts from its mean position, goes to extreme on one side and then to extreme on the other side and finally comes to the mean position.

20.Periodic motion is also known as-
(A) Rectilinear motion.
(B) Circular motion.
(C) Non uniform motion.
(D) Oscillatory motion.

21.In a uniform motion
(A) Average speed is the same as the actual speed.
(B) The object is moving along a straight line.
(C) The object is moving with a constant speed.
(D) All the three statements are true.

22.If a car is moving with a speed of 45 kilometers per hour, it implies that-
(A) It will cover a distance of 45 metres in one minute.
(B) It will cover a distance of 45 kilometers in one hour.
(C) It will cover a distance of 45 miles in one hour.
(D) It is moving with a constant speed of 45 kilometers per hour.

23.Periodic motion is the motion which-
(A) Repeats itself after a regular interval of time.
(B) Repeats itself after anindefinite time.
(C) Does not repeat itself.
(D) None of them.

24.Time intervals shorter than a day can be measured by using a-
(A) Clock.
(B) Watch.
(C) Stop Watch.
(D) Clock, watch or stop watch.

25.If the speed of an object moving along a straight line keeps on changing,
(A) The motion is said to be a uniform motion.
(B) The motion is said to be a non uniform motion.
(C) The object is said to be stationary.
(D) The motion is said to be a fast motion.

26.A year was fixed as the time taken by-
(A) The Earth to complete one revolution around its axis.
(B) The Earth to complete one revolution around the Sun.
(C) The moon to complete one revolution around the Earth.
(D) The satellite to complete one revolution around the Earth.

27.The time between one new moon to the next can be called a-
(A) Month.
(B) Year.
(C) Day.
(D) Interval.

28.The time between one sunrise and the next is known as a-
(A) Month.
(B) Year.
(C) Day.
(D) Interval.

29.Speed is directly measured by using a device called-
(A) Odometer.
(B) Speedometer.
(C) Both (1) and (2).
(D) None of these.

30.The most common example of periodic motion is-
(A) Digital clock.
(B) Simple Pendulum.
(C) Moving car.
(D) Movement of a pedestrian.

31.If the distance-time graph is a straight line, it indicates-
(A) The speed of the object keeps on changing.
(B) The object is moving with a constant speed.
(C) The object is not moving.
(D) None of these.

32.A faster moving object covers-
(A) Less distance in more time.
(B) More distance in more time.
(C) Less distance in shorter time.
(D) More distance in shorter time.

33.A simple pendulum consists of-
(A) Small metallic ball - bob only.
(B) A string only.
(C) Small metallic ball suspended from a rigid stand by a string.
(D) None of these.

34.The distance-time graph can be used to find-
(A) Distance moved by an object at any instant of time.
(B) Speed of the object.
(C) Distance moved by an object during definite time intervals.
(D) All of these.

35.A dog is running at a speed of 36 km/h. Its speed in m/s will be-
(A) 10.
(B) 3.6.
(C) 100.
(D) 360.

36.The total time taken by a vehicle to cover the total distance is given by-
(A) total distance covered Total time taken = average speed
(B) average speed Total time taken = total distance covered
(C) total distance covered Total time taken = speed
(D) speed Total time taken = total distance covered

37.Pendulum is used in-
(A) Water clocks.
(B) Pendulum clocks.
(C) Sundials.
(D) All of them.

38.Unit of speed is-
(A) m/s.
(B) m/min.
(C) km/h.
(D) All of them.

39.The to and fro motion is an example of-
(A) Circulatory motion.
(B) Oscillatory motion.
(C) Periodic motion. (D) Both (b) and (c).

40.The distance time graph is a straight line when-
(A) An object changes its speed frequently.
(B) An object changes its direction frequently. 
(C) An object changes is in rest position.
(D) An object moves with a constant speed.

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41.A simple pendulum takes 15 seconds to complete 5 oscillations.What is the time period of the pendulum?

42.How do we know an object is moving faster?

43.If a car is moving with a speed of 5 km/h on a highway find the distance travelled by the car in 3 hours?

44.The distance between two stations is 240 km. A train takes 6 hours to cover this distance. Calculate the speed of the train.

45.Explain how motion of a child on a see-saw is an oscillatory motion.

46.What is the nature of distance-time graph for the motion of an object moving with a constant speed?

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47.Explain how in ancient times, a day, a month and a year was measured.

48.Explain the different positions of the bob of the simple pendulum while it oscillates.

49.Priya takes 20 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/sec, calculate the distance between her school and her house.

50.A car is moving with speed 72 km/hr. Convert this speed into metre/sec.

51.What are the import point to be kept in mind while choosing the scale for a graph?

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52.What are the points that should be kept in mind while choosing scale for drawing a graph?

53.Show the distance-time graph for the motion in the following cases:
(i) A car moving with a constant speed.
(ii) A car parked on a side road.
(iii) A car moving with non-uniform speed.

54.What are the uses of distance-time graphs?

55.Describe a simple pendulum with the help of a neat labeled diagram.

56.Suggest an activity to measure the time period of the simple pendulum.

Q1. Define speed. State its S. I. unit.

Q2. Differentiate between uniform and non-uniform motion.

Q3. Describe a simple pendulum. Draw a diagram. What kind of motion does it show?

Q4. For a simple pendulum; define:-
a) One oscillation
b) Time period
c) Frequency

Q5. A truck travels a distance of 540 km in 4.5 hours. Calculate its speed.

Q6. The distance between two stations is 1995 km. How much time it will take to cover this distance at an average speed of 19 km/h?

Q7. A car takes 20 minutes to cover a distance of 15 km. Calculate its speed in km/h.

Q8. Plot the distance – time graph from the following data also find the speed using the graph . Calculate the distance travelled in 4.5s.

Q9. Name the following:

1. The watches and clocks used nowadays which have an electric circuit.

2. The scientist who found that, a pendulum of a given length takes the same time to complete one oscillation. 

3. The clocks that were used to measure time, before the pendulum clock became popular.

Q10. Fill in the blanks:

1. One microsecond is ____________________ of a second.

2. One nanosecond is _____________________ of a second.

3. ___________ of objects helps us to decide which one is moving faster than the other.

4. The speed of a vehicle is measured with a device called ______________.

5. ________________ measures the distance moved by the vehicle.

6. All clocks are based on _______________ events.

7. ________________ is used to measure short intervals of time.

8. 36 km/h is same as _____________ m/s.

9. The slope of a distance-time graph represents ____________.

10. The distance-time graph for the motion of an object with a constant speed is a _______________ line.

Q11. Choose the correct option:

1. A repetitive motion which takes place at equal intervals of time is called:
a) random motion
b) rectilinear motion
c) curvilinear motion
d) periodic motion

2. Time period of a pendulum does not depend upon:
a) mass of the bob
b)size of the bob
c) amplitude
d) all of these

3. While plotting a graph one must take care to plot:
a) The independent quantity on Y-axis
b) The independent quantity on X-axis
c) The dependent quantity on X-axis
d) None of these

4. If the distance-time graph is a curved line:
a) A non-uniform speed is maintained by the object
b) The object covers unequal distances in equal intervals of time
c) Both a) and b)
d) None of these

I Fill in the blanks :

1. The distance moved by an object in a unit time is called its ___________.

2. Basic unit of measuring speed is _____________.

3. ______________ events are used for the measurement of time.

4. A _______________ consists of a small metallic ball or a piece of stone suspended from a rigid stand by a thread.

5. The metallic ball is called the ______________ of the pendulum.

6. The to and fro motion of a simple pendulum is an example of a ____________ or an ______________ motion.

7. Meter that measures the distance moved by the vehicle is known as ____________________.

8. Motion of objects can be presented in pictorial from by their __________.

9. Rockets, launching satellites into earth’s orbit often attain speeds up to ___________________ Km/s.

10. The basic unit of time is ________________.

II. Write true or false :

1. A year was fixed as the time taken by the earth to complete one revolution of the sun.

2. A nanosecond is one billionth of a second.

3. The motion of a pendulum is an example of non-periodic motion.

4. In ancient time people used to measure time with help of clock or wristwatch.

5. The time taken by the pendulum to complete one oscillation is called its time period.

6. The graph for non-uniform motion is a curve line.

III Name the following :

1. Name any two ancient – time measuring devices.

2. Name the scientist who discovered pendulum.

3. Name the meter in vehicles which records the speed directly in Km/h.

4. Name the ancient clock located at Jantar Mantar, Delhi.

IV Define the following :

1. Motion

2. Speed

3. Oscillation

V Distinguish between :

1. Uniform motion and Non-uniform motion

- A body is said to be in motion if it changes its position with respect to a reference point.
-Motion and rest are relative terms for eg. If A and B are sitting in a moving car and a third person C is standing outside than A and B are at rest w.r.t. each other but in motion w.r.t. C.
- Speed is defined as distance travelled per unit time i.e. speed = distance/time
- Uniform motion – A body is said to have uniform motion if it moves with constant speed in same direction.
- Non uniform motion – A body is said to have non uniform motion if either speed or direction of the moving body changes.
- Average speed = total distance travelled /total time taken (for non uniform motion)
-S.I unit of speed is m/s.
- Speed = distance/time
- Distance = speed x time
- Time = distance / speed

MEASUREMENT OF TIME-
- All of the clocks make use of some periodic motion. One of the most well known periodic motions is that of a simple pendulum.
- The to and fro motion of a simple pendulum is an example of oscillatory motion which is a periodic motion.
- The time taken by a pendulum to complete one oscillation is called its time period.
- The basic unit of time is second.

ASSIGNMENT

Q1 Define motion.

Q2 Is the movement of the earth around sun uniform or non uniform motion? Explain.

Q3 In which form of motion average speed is equal to the actual speed?

Q4 Classify the following as motion along a straight line, circular or oscillatorya) hands of an athlete in a race
b) pedals of a bicycle in motion
c) motion of a swing
d) motion of a merry go round
e) motion of a freely falling body

Q5 Differentiate between uniform and non uniform motion.

Q6 What is measured by an odometer and a speedometer in a vehicle?

Q7 What are quartz clocks?

Q8 Convert
(a) 36 Km/hr to m/s
(b) 5 m/s to Km/hr

Q9 A boy cycles down from his house to his school at a speed of 18Km/hr and reaches there in 20 minutes. How far is the school from his house?

Q10 A man covers a total distance of 750 Km in his car with an average speed of 50 Km/hr. How much time does he take?

Q11 A body covers a distance of 20 Km in 20 minutes. Calculate its speed in Km/hr and m/s.

Q12 A simple pendulum completes 40 oscillations in 20 seconds. What is the time period of the pendulum?

Q13 Draw the distance – time graph for a body which moves at a speed of 2m/s for first five seconds than stays at rest for next 2 seconds and again move at a speed of 2m/s for next 3 seconds.

HEAT – ASSIGNMENT

Q1 Define heat. Write its S.I unit.

Q2 Define temperature. Write its S.I unit.

Q3 which form of energy is gained by the molecules of a substance on heating?

Q4 Differentiate between
(a) heat and temperature
(b) lab and clinical thermometer
(c) Conduction, convection and radiation

Q5 Can we use a lab thermometer for measuring our body temperature? Give reasons for your answer.

Q6 Why is there a kink in the capillary tube of a clinical thermometer?

Q7 Give reasons—
(a) Ice is wrapped in a woolen cloth to prevent it from melting.
(b) A metal tea pot is provided with a wooden handle.
© It saves fuel if we cook food in a vessel which is blackened at the bottom and polished from sides.
(d) We prefer two blankets joined together than a single thick blanket on a cold winter night.
(e) Coastal areas have moderate climate.
(f) Ventilators in the houses are provided at the top.

Q8 If we touch a piece of ice , our hand feels cold. Why?

Q9 Two similar beakers containing equal volumes of hot water are placed on a bench. The outer surface of one beaker is painted with shiny white paint and the other with dull black paint. Which of them will cool down faster?

Q10 Give one example each of transfer of heat by
(a) conduction
(b) convection
(c) radiation

Q11 Pick out the good and bad conductor of heat from this list ---- copper , mercury,leather,wool,air,water,iron,brick,straw,card board,.brass,plastic,stainless steel .

Q12 Explain the process by which a container filled with water gets heated.

Q13 Give any four reasons for using mercury in a thermometer.

1. Give one example of each of the following

a. Motion in a straight line

b. Circular motion

c. Oscillatory motion

2. Write the deference between uniform and non- uniform motion.

3. Give the formula to calculate average speed of a moving car.