Motion Class 9 Science Multiple Choice Questions & Answers

Question-1. 1 km/ h =….................m/s

1. 3/50
2. 18/5
3. 50/3
4. 5/18

Question-2. 180° plane angle is equal to

1. p/2 radian
2. p radian
3. 2p radian
4. none of these

Question-3. A body is thrown vertically upward with velocity u, the greatest height h to which it will rise is…..........

1. u/g
2. u2/2g
3. u2/g
4. u/2g

Question-4. A body moves in a uniform circular motion

1. it is moving with constant velocity.
2. its acceleration is zero
3. the body has an acceleration
4. none of these

Question-5. A body moving along a straight line at 20 m/s undergoes an acceleration of -4 m/s2. After two seconds its speed will be -

1. -8 m/s
2. 12 m/s
3. 16 m/s
4. 28 m/s.

Question-6. A body performs an accelerated motion, with uniform speed. The motion of body is

1. Linear
2. Circular
3. Parabolic
4. Irregular

Question-7. A body whose speed is constant

1. must be accelerated
2. might be accelerated
3. has a constant velocity
4. can not be accelerated.

Question-8. A boy throws a ball up and catches it when the ball falls back. In which part of the motion the ball is accelerating?

1. During downward motion
2. When the ball comes to rest
3. During upward motion
4. When the boy catches the ball

Question-9. A car goes from a town A to another town B with a speed of 40 km/h and returns back to the town A with a speed of 60 km/h. The average speed of the car during the complete journey is -

1. 48 km/h
2. 50 km/h
3. zero
4. none of these.

Question-10. A car is travelling at a speed of 90 km/h. Brakes are applied so as to produce a uniform acceleration of ? 0.5 m/s2. Find how far the car will go before it is brought to rest?

1. 8100 m
2. 900 m
3. 625 m
4. 620 m

Question-11. A man is moving with 36 kmph. The time of reaction is 0.9 seconds. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s2, the total distance covered before he stops is

1. 19 m
2. 17 m
3. 16 m
4. 18 m

Question-12. A man is moving with 36 kmph. The time of reaction is 0.9 seconds. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s2, the total distance covered before he stops is

1. 19 m
2. 17 m
3. 16 m
4. 18 m

Question-13. A man travels a distance of 20 km from his home to office, and 10 km towards his house back. Then the displacement covered by the man in the whole trip is

1. 30 Km
2. 10 Km
3. zero Km
4. 50 Km

Question-14. A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance s­1 in the first 10 seconds and distance s2 in the next 10 seconds then,

1. s2 = s1
2. s2 = 2s1
3. s2 = 3s1
4. s2 = 4s1

Question-15. A particle is moving in a circular path of radius r. The displacement after half a circle would be

1. Zero
2. p r
3. 2 r
4. 2p r

Question-16. a particle moves with uniform positive acceleration. Its velocity-time graph will be

1. a straight line parallel to the time axis
2. a straight line inclined at an obtuse angle to the time axis
3. a straight line inclined at an acute angle to the time axis
4. none of these.

Question-17. A person travels distance pR along the circumference of a circle of radius R. Displacement of the person is

1. R
2. 2R
3. 2pR
4. zero

Question-18. Acceleration is a vector quantity, which indicates that its value

1. Can be positive, negative or zero
2. Is always positive
3. Is always negative
4. Is zero

Question-19. An example of a body moving with constant speed but still accelerating is

1. A body moving in a helical path with constant speed
2. A body moving with constant speed on a straight road
3. A body moving with constant speed in a circular path
4. A body moving with constant speed on a straight railway track

Question-20. An object moves along a curved path. The following quantities may remain constant during its motion.

1. speed
2. velocity
3. magnitude of acceleration
4. both a and c