MCQ Questions for Class 9 Science Chapter 9 Force and Laws of Motion

MCQ Questions for Class 9 Science Chapter 9 Force and Laws of Motion can help you better understand the material, identify your weaknesses, and focus your studying. The questions are designed in such a way that they cover all the important topics of the syllabus.

When used in learning, Chapter 9 Class 9 Science CBSE MCQ Questions with answers can encourage learners to explore more topics and make the learning process more fun. It can provide a quick way to check understanding and identify any areas that may need more revision.

Chapter 9 Force and Laws of Motion Class 9 Science MCQ Questions

1. If A and B are two objects with masses 6 kg and 34 kg respectively, then
(a) A has more inertia than B
(b) B has more inertia than A
(c) A and B have same inertia
(d) none of the two has inertia.
▶ (b) B has more inertia than A

2. A cannon after firing recoils due to
(a) conservation of energy
(b) backward thrust of gases produced
(c) Newton’s third law of motion
(d) Newton’s first law of motion
▶ (c) Newton’s third law of motion

3. A passenger in a moving train tosses a coin which falls behind him. It means that motion of the train is
(a) accelerated
(b) uniform
(c) retarded
(d) along circular tracks
▶ (a) accelerated

4. A number of forces acting on a body changes velocity of the body. The forces cannot be
(a) paralleled
(b) unbalanced
(c) balanced
(d) inclined
▶ (c) balanced

5. The inertia of a moving object depends on
(a) momentum of the object
(b) speed of the object
(c) mass of the object
(d) shape of the object
▶ (c) mass of the object

6. An object of mass 2 kg is sliding with a constant velocity of 4 ms^-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
▶ (b) 0 N

7. If a body is moving alone a constant speed, it may be assumed that
(a) a net force is pushing it forward
(b) the sum of only vertical forces is zero
(c) the buoyant force is greater than gravity
(d) the sum of all forces is zero
▶ (d) the sum of all forces is zero

8. Swimming is possible on account of
(a) First law of motion
(b) Second law of motion
(c) Third law of motion
(d) Newton’s law of gravitation
▶ (c) Third law of motion

9. If the mass of a body is doubled and its velocity becomes half, then the linear momentum of the body will
(a) remain same
(b) become double
(c) become half
(d) become four times
▶ (a) remain same

10. Newton’s third law is equivalent to the
(a) law of conservation of linear momentum
(b) law of conservation of angular momentum
(c) law of conservation of energy
(d) law of conservation of energy and mass
▶ (a) law of conservation of linear momentum

11. A body is accelerating in a straight line. The unbalanced force acts
(a) in the direction of motion of the body.
(b) in a direction opposite to the direction of motion.
(c) in a direction perpendicular to the direction of motion of the body.
(d) none of these
▶ (a) in the direction of motion of the body.

12. When a number of forces acting simultaneously on a body bring about a change in its state of rest or of uniform motion in a straight line, then these forces acting on the body are said to be
(a) balanced forces
(b) equal forces
(c) unbalanced forces
(d) opposite forces
▶ (d) opposite forces

13. The momentum of a body of given mass is proportional to its
(a) velocity
(b) size
(c) shape
(d) all of these
▶ (a) velocity

14. A man is standing on a boat in still water. If he walks towards the shore, then the boat will
(a) move away from the shore
(b) move towards the shore
(c) remain stationary
(d) none of these
▶ (a) move away from the shore

15. A man getting down a running bus, falls forward because
(a) due to inertia of rest, road is left behind and man reaches forward
(b) due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road
(c) he leans forward as a matter of habit.
(d) of the combined effect of al the three factors stated in (a), (b) and (c)
▶ (b) due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road

16. A ball is thrown vertically upward in a train moving with uniform velocity. The ball will
(a) fall behind the thrower
(b) fall ahead of the thrower
(c) return back to the thrower
(d) fall on the left of the thrower
▶ (c) return back to the thrower

17. The momentum of an object at a given instant is independent of its
(a) inertia
(b) mass
(c) velocity
(d) acceleration
▶ (d) acceleration

18. A cannon after firing recoils due to
(a) conservation of energy
(b) Newton’s third law of motion
(c) Newton’s first law of motion
(d) none of these
▶ (b) Newton’s third law of motion

19. A hockey player pushes the ball on the ground. It comes to rest after travelling certain distance because
(a) the player stops pushing the ball.
(b) balanced force acts on the ball.
(c) the opposing force acts on the ball.
(d) none of these
▶ (c) the opposing force acts on the ball.

20. When we stop pedalling, the bicycle begins to slow down. This is because of the
(a) Frictional force acting along the direction of motion of bicycle
(b) Air resistance which is in the direction of motion
(c) Frictional force acting opposite to the direction of motion of bicycle by the road
(d) Nature of the bicycle to stop after some time
▶ (d) Nature of the bicycle to stop after some time

21. A body at rest explodes into two equal parts. Then
(a) they move with different speeds in different directions
(b) they move with different speeds in same direction
(c) they move with same speed in same direction
(d) they move with same speed in opposite directions
▶ (d) they move with same speed in opposite directions

22. A football has lesser inertia than a stone of the same size because
(a) football has more air inside than the stone
(b) football has less air inside than the stone
(c) football has less mass than the stone
(d) football has more mass than the stone
▶ (c) football has less mass than the stone

23. When a body is stationary
(a) There is no force acting on it
(b) The force acting on it not in contact with it
(c) The combination of forces acting on it balances each other
(d) The body is in vacuum
▶ (c) The combination of forces acting on it balances each other

24. An unbalanced force acts on a body. The body
(a) must remain in same state
(b) must move with uniform velocity
(c) must be accelerated
(d) must remain at rest
▶ (c) must be accelerated

25. If an object is in a state of equilibrium
(a) It is at rest
(b) It is in motion at constant velocity
(c) It is in free fall
(d) may be more than one of the above
▶ (d) may be more than one of the above