High School Physics

Force and Laws of Motion class 9 MCQ

Last updated on July 5th, 2023 at 03:17 pm

In this post, we present a set of multiple-choice questions on Force and Laws of Motion class 9 MCQ. The answers to these MCQs are given after each question.

Also, read: Force and Laws of Motion class 9 Numericals

Force and Laws of Motion class 9 MCQ (multiple-choice questions and answers)

1] An object of mass 2 kg is sliding with a constant velocity of 4 m/s on a frictionless horizontal table. The force required to keep this object moving with the same velocity is:
(a) 32 N (b) 0 N (c) 2 N (d) 8 N

(b) 0 N

2} The physical quantity which makes it easier to accelerate a small car than a large car is measured in the
unit of :
(a) m/s (b) kg (c) kg.m/s (d) kg.m/s2

(b) kg

3] According to the third law of motion, action, and reaction:
(a) always act on the same body but in opposite directions
(b) always act on different bodies in opposite directions
(c) have the same magnitudes and directions
(d) act on either body at normal to each other

(b) always act on different bodies in opposite directions

4] The rockets work on the principle of conservation of:
(a) mass (b) energy (c) momentum (d) velocity

(c) momentum

5] The unit of measuring the momentum of a moving body is :
(a) m s–1 (b) kg.m s–1 (c) kg.m s–2 (d) Nm2 kg–2

(b) kg.m s–1

6] A boy of mass 50 kg standing on the ground exerts a force of 500 N on the ground. The force exerted by the ground on the boy will be :
(a) 50 N (b) 25000 N (c) 10 N (d) 500 N

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(d) 500 N

7] A Honda City car, a Maruti Alto car, a Tata Nano car, and a Mahindra Scorpio car, all are running at the
same speed of 50 m/s under identical conditions.
If all these cars are hit from behind with the same force and they continue to move forward, the maximum acceleration will be produced in:
(a) Honda City (b) Maruti Alto (c) Tata Nano (d) Mahindra Scorpio

(c) Tata Nano

8] The acceleration produced by a force of 5 N acting on a mass of 20 kg in m/s2 is :
(a) 4 (b) 100 (c) 0.25 (d) 2.5

(c) 0.25

9] Which of the following situations involves Newton’s second law of motion?
(a) a force can stop a lighter vehicle as well as a heavier vehicle which are moving
(b) a force can accelerate a lighter vehicle more easily than a heavier vehicle
(c) a force exerted by a lighter vehicle on collision with heavier vehicle results in both vehicles coming
to a standstill
(d) a force exerted by the escaping air from a balloon in the downward direction makes the balloon go
upwards

(b) a force can accelerate a lighter vehicle more easily than a heavier vehicle

10] A fielder pulls his hands backward after catching the cricket ball. This enables the fielder to :
(a) exert larger force on the ball (b) reduce the force exerted by the ball
(c) increase the rate of change of momentum (d) keep the ball in hands firmly

(b) reduce the force exerted by the ball

Practice MCQ on Force and Laws of Motion class 9

1. Which of the following statement is not correct for an object moving along a straight path
in an accelerated motion?
(a) Its speed keeps changing
(b) Its velocity always changes
(c) It always goes away from the earth
(d) A force is always acting on it
2. The forces of action and reaction are
(a) always equal only
(b) always equal and opposite
(c) always equal but in the same direction
(d) always unequal and opposite.
3. According to the third law of motion, action and reaction
(a) always act on the same body
(b) always act on different bodies in opposite directions
(c) have the same magnitude and directions
(d) act on either body at normal to each other
4. The action and reaction forces at
(a) on different bodies always
(b) on somebody always
(c) on the same body, sometimes
(d) on different bodies, sometimes
5. A goalkeeper in a game of football pulls his hands backward after holding the ball shot at
the goal. This enables the goalkeeper to
(a) exert larger force on the ball
(b) reduce the force exerted by the ball on the hands
(c) increase the rate of change of momentum
(d) decrease the rate of change of momentum
6. The inertia of an object tends to cause the object
(a) to increase its speed
(b) to decrease its speed
(c) to resist any change in its state of motion
(d) to decelerate due to friction
7. The principle of conservation of linear momentum is deduced from
(a) Newton’s first law
(b) Newton’s second law
(c) Newton’s third law
(d) none of the above
8. The function of mudguards is based on
(a) inertia of rest
(b) inertia of direction
(c) inertia of motion
(d) none of the above
9. The force of action and reaction
(a) always cancel each other
(b) never cancel
(c) cancel sometimes
(d) cannot say
10. A passenger in a moving train tosses a coin that falls behind him. It means that the motion of
the train is
(a) accelerated
(b) uniform
(c) retarded
(d) along circular tracks
11. An object of mass 2 kg is sliding with a constant velocity of 4 m s–1 on a frictionless
horizontal table. The force required to keep the object moving with the same velocity is
(a) 32 N
(b) 0 N
(c) 2 N
(d) 8 N
12. Rocket works on the principle of conservation of
(a) mass
(b) energy
(c) momentum
(d) velocity
13. A water tanker filled up to 2
3
of its height is moving with a uniform speed. On sudden
application of the brake, the water in the tank would
(a) move backward
(b) move forward
(c) be unaffected
(d) rise upwards
14. The inertia of a body in linear motion is measured by its
(a) mass
(b) momentum
(c) velocity
(d) none of the above
15. What mass of a body can attain an acceleration of 5m/s2 under a force of 250 N?
(a) 5 kg
(b) 250 kg
(c) 50 kg
(d) 10 kg