class 9 / physics worksheet-1 / chapter-8 / motion

Class 9 – Physics - Ch 8 – Motion

(WORKSHEET - 1)

Subtopic –

1.) INTRODUCTION ON MOTION & REST

2.) DESCRIBING MOTION—distance & displacement

Fill in the blanks

1. If the position of an object does not change with time, it is said to be at _____.
2. Rest and Motion are ___________ (absolute/relative) terms
3. The study of motion without taking into account the cause of motion is called ______ (kinematics/dynamics).
4. An object is said to be at ________ (rest/motion), if it changes its position with respect to its surroundings in a given time
5. Distance is the length of ______(actual/shortest) path traveled by a body in a given time.
6. Displacement is the ______ (actual/shortest) path covered by a moving object from the initial point of reference in a specified direction.
7. Distance is a _______ (scalar/vector) physical quantity while displacement is a _______ (scalar/vector) physical quantity. 

8. SI unit of distance is _____ (meter / kilometer)

9. SI unit of displacement is _____ (meter / kilometer).

10. Movement of dust and the movement of leaves, infer the motion of air _____    (directly / indirectly).

MCQs

1.  A scalar quantity has ______________?

(a) Magnitude only 
(b) direction only
(c) both direction and magnitude 
(d) none of these.

2.  A vector quantity has ______________?

(a) Magnitude only 
(b) direction only
(c) both direction and magnitude 
(d) none of these.

3.  The SI unit of displacement is-

(a) m
(b) km
(c) cm
(d) am

4.  If a body travelled to some path then its distance-

(a) can be positive
(b) can be zero
(c) can be negative
(d) all are true.

5.  If a body travelled to some path then its displacement -

(a) can be positive
(b) can be zero
(c) can be negative
(d) all are true.

6.  Distance is always ≥ displacement -

(a) true
(b) false
(c) both (a) and (b)
(d) neither (a) nor (b).

7.  A scalar quantity-

(a) distance
(b) displacement
(c) both (a) and (b)
(d) neither (a) nor (b).

8.  A vector quantity-

(a) distance
(b) displacement
(c) both (a) and (b)
(d) neither (a) nor (b).

9.  In the given figure, object starts its motion at point A,GO TO B-C-D  and again came back to A. find DISTANCE at point A.

(a) 0
(b) 16
(c) can’t say
(d) 8

10.     In the given figure, object starts its motion at point A,GO TO B-C-D  and again came back to A. find DISPLACEMENT at point A.

(a) 0
(b) 16
(c) can’t say
(d) 8

Q & A’s

1.  What do you mean by a body in motion or at rest?

2. Are motion and rest absolute and relative? Explain with example.

3. What does the odometer of an automobile measures?

4. Give 2 situations where the motion is inferred through “direct evidences” and “indirect evidences”.

5. What do you mean by “reference point”.

6. Differentiate between “distance” and “displacement”.

7.  If the displacement of a body is zero, is the distance by it is also zero? Comment.

8.  Is the magnitude of the displacement and distance of an object can be equal? Justify.

9.  Show that displacement of a body is either smaller or equal to the distance of the body.

10.   Chancy drives her scooter 7 kilometers north.  She stops for lunch and then drives 5 kilometers east.  What distance did she cover?  What was her displacement?

Solve the following

1. In figure-

John walks from the point A to B to C. What does the distance he travels? What is the displacement?

2. Bessie the fox and Sally the rabbit both traveled from point “A” to point “B.” Sally traveled in a straight line and Bessie did not.

A. What distance does Bessie the fox travel?

B. What distance does Sally the rabbit travel?

C. What is Bessie the fox’s displacement?

D. What is Sally the rabbit’s displacement?

3.  

The track is 100 meter around.

a.) If the car travels once around the racetrack, what distance does it travel?

b.) If the car travels twice around the racetrack, what distance does it travel?

c.) If the car travels once around the racetrack, what is its displacement?

4. An athlete completes one round of a circular path of diameter 200 m in 40 seconds. What will be the distance covered and displacement at the end of 2 min 20 seconds?

5. What are the distance and the displacement of the race car drivers in completing path of length 500 m?

6. Anthony walks to the pizza place for lunch.  He walk 1 km east, then 1 km south and then 1 km east again.  What distance did he cover?  What was his displacement?

7. A particle moves along a circle of radius ‘R’. it starts  from A and moves in antilock direction. Calculate the distance travelled by particle

(a) From A to B                                      (b) From A to C

 (c) From A to D                                     (d) for complete 2 rounds.

 8. A car moves 100 m due east and then 25 m due west, (a) What is the distance

Covered by the car? (b) What is its displacement?

9. What is the displacement of the cross-country team if they begin at the school, run 10 miles and finish back at the school?

10. Look at the picture given below. An object moves from point A through B, C, D, E. and stops at point F.

a) Find final displacement

b)Find distance taken from point A to D.