Force and Laws of Motion Class 9 MCQ

Force and Laws of Motion Class 9 MCQ: Below are NCERT MCQ questions for Class 9 Science, Chapter 9 “Force and Laws of Motion,” designed by subject experts. We designed these Force and Law of motion Class 9 MCQ to align with the latest exam patterns and help students grasp the concepts effectively. Alongside the questions, answers are provided to facilitate better understanding. Students can rely on these Class 9 MCQs and practise them regularly. Students can also refer to NCERT Solutions for Class 9 Science Chapter 9 “Force and Laws of Motion” for better understanding of the chapter.

Class 9 Science MCQs – Chapter-wise

1. Matter in Our Surroundings
2. Is Matter Around Us Pure
3. Atoms and Molecules
4. Structure of Atom
5. The Fundamental Unit of Life

Force and Laws of Motion – Introduction

These principles, formulated by Sir Isaac Newton, are fundamental to understanding the behavior of objects in motion.

• Force: Defined as any influence capable of causing a change in an object’s velocity, force encompasses pushes, pulls, and interactions resulting in acceleration.
• Newton’s First Law (Law of Inertia): Objects remain at rest or in uniform motion unless acted upon by an external force. This law highlights the concept of inertia, where objects resist changes in their state of motion.
• Newton’s Second Law: Quantifies the relationship between force, mass, and acceleration. It states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
• Newton’s Third Law: Asserts that for every action, there is an equal and opposite reaction. This law elucidates the principle that when one object exerts a force on another, the second object simultaneously exerts an equal and opposite force on the first.

Together, these laws provide a comprehensive framework for explaining and predicting the motion of objects, serving as foundational principles in the field of physics.

Force and Laws of Motion MCQ Class 9 Questions with Answers

Q1. What is the ultimate outcome when balanced forces act upon an object?
a) The object remains stationary.
b) The object accelerates.
c) The object decelerates.
d) The object moves at a constant velocity.
Answer: a) The object remains stationary.

Q2. According to the fundamental law of motion, an object persists in its state of rest or uniform motion unless influenced by what?
a) Unbalanced forces.
b) Balanced forces.
c) Frictional forces.
d) Gravitational forces.
Answer: a) Unbalanced forces.

Q3. Inertia embodies the resistance of an object to alterations in which of the following?
a) Direction.
b) Velocity.
c) Acceleration.
d) All the mentioned.
Answer: d) All the mentioned.

Q4. As per the second law of motion, what parameter is directly linked to the acceleration of an object?
a) Its mass.
b) Its inertia.
c) The applied force.
d) None of the above.
Answer: c) The applied force.

Q5. What is the precise mathematical expression representing the second law of motion?
a) F = m × a.
b) F = m / a.
c) F = m + a.
d) F = m – a.
Answer: a) F = m × a.

Also Check: NCERT Book Class 9 Science

Q6. The third law of motion stipulates that for every action, there exists an equal and opposite reaction. What does this axiom entail?
a) The reaction force is always equal in magnitude.
b) The action and reaction forces act on different objects.
c) The reaction force always acts in the opposite direction.
d) All the mentioned.
Answer: d) All the mentioned.

Q7. If a person exerts a force of 500 N against a wall, what is the corresponding reaction force applied by the wall?
a) 500 N.
b) 0 N.
c) It depends on the mass of the wall.
d) None of the above.
Answer: b) 0 N.

Q8. Which among the subsequent scenarios exemplifies an unbalanced force?
a) A book resting on a table.
b) A car moving at a constant speed on a straight road.
c) A ball falling freely towards the ground.
d) A person exerting force to move a heavy box.
Answer: d) A person exerting force to move a heavy box.

Q9. Which of the following scenarios best illustrates Newton’s first law of motion?
a) A ball rolling down a hill.
b) A book sliding on a table coming to a stop.
c) A person riding a bicycle at a steady pace.
d) A car accelerating after being at rest.
Answer: c) A person riding a bicycle at a steady pace.

Q10. When a force of 10 N is applied to an object weighing 2 kg, what would be the resultant acceleration of the object?
a) 20 m/s^2.
b) 5 m/s^2.
c) 2 m/s^2.
d) 0.2 m/s^2.
Answer: b) 5 m/s^2.

Force and Laws of Motion Class 9 MCQ (Moderate Level Questions)

Here are some more high-level multiple-choice questions on the topic of “Force and Laws of Motion” for Class 9, along with their answers:

1. Which of the following is an example of Newton’s third law of motion?
a) A rocket launching into space
b) A car accelerating on a straight road
c) A person pushing a box across the floor
d) A book resting on a table
Answer: a) A rocket launching into space

2. When a person jumps from a boat to the shore, the boat moves backward due to:
a) Action-reaction force
b) Gravitational force
c) Frictional force
d) Buoyant force
Answer: a) Action-reaction force

3. An object of mass 10 kg is subjected to a force of 20 N. What is the acceleration of the object?
a) 0.5 m/s²
b) 2 m/s²
c) 200 m/s²
d) 10 m/s²
Answer: b) 2 m/s²

4. Which of the following is a unit of force in the SI system?
a) Kilogram
b) Meter per second
c) Newton
d) Pascal
Answer: c) Newton

5. A force of 50 N is applied to an object of mass 10 kg. What is the net force acting on the object if it is moving with a constant velocity?
a) 5 N
b) 10 N
c) 50 N
d) 0 N
Answer: d) 0 N

6. When a car accelerates on a straight road, the force responsible for its acceleration is primarily due to:
a) Frictional force
b) Gravitational force
c) Applied force
d) Normal force
Answer: c) Applied force

7. According to Newton’s second law of motion, the acceleration of an object is directly proportional to the:
a) Net force acting on the object
b) Mass of the object
c) Velocity of the object
d) Weight of the object
Answer: a) Net force acting on the object

8. Which of the following is an example of inertia?
a) A ball rolling down a hill
b) A car turning around a curve
c) A book at rest on a table remaining stationary
d) A person pushing a heavy box
Answer: c) A book at rest on a table remaining stationary

9. If the mass of an object is doubled while the force acting on it remains constant, what happens to its acceleration?
a) It doubles
b) It remains the same
c) It halves
d) It quadruples
Answer: c) It halves

10. Which of Newton’s laws states that an object will remain at rest or in uniform motion unless acted upon by an external force?
a) Newton’s First Law
b) Newton’s Second Law
c) Newton’s Third Law
d) Law of Gravitation
Answer: a) Newton’s First Law