Newton's Third Law Motion Questions

Newton’s third law of motion is a fundamental law of physics that states that for every action, there is an equal and opposite reaction. Example: A swimmer pushes against the water.

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Important Newton’s Third Law Motion Questions with Answers

1. How many laws of motion are put forth by Newton?

1. 3
2. 5
3. 6
4. 7

Answer: a) 3

Explanation: Newton has put forth 3 laws of motion.

2. What is the force acting between the Sun and the Earth?

1. Electric force
2. Magnetic force
3. Gravitational force
4. Electromagnetic force

Answer: c) Gravitational force

Explanation: Gravity is the force that pulls two bodies together, it acts between the earth and the Sun.

3. Newton’s first law of motion is known as _______

1. The law of inertia
2. The law of mass
3. The law of momentum
4. The law of velocity

Answer: a) The law of inertia

Explanation: Newton’s first law of motion is known as the law of inertia.

4. When an object is at rest, what would be the velocity and acceleration?

1. Velocity = infinity and acceleration = infinity
2. Velocity = 0 and acceleration = 0
3. Velocity = infinity and acceleration = 0
4. Velocity = 0 and acceleration = infinity

Answer: Velocity = 0 and acceleration = 0

Explanation: When the object is at rest, no motion is involved and hence velocity = 0 and acceleration = 0.

5. How is the force classified?

Force classified as: Contact force and Non-contact force.

6. Choose the correct answer: Which is the contact force?

1. Gravitational force
2. Frictional force

Answer: b) Frictional force

Explanation: Frictional force is the best example of the contact force.

7. When two bodies interact, they exert force on each other, and these forces are known as _____

1. Friction-gravitation pair
2. Action-reaction pair
3. Ground-sky pair
4. Air-water pair

Answer: b) Action-reaction pair

Explanation: As we know, forces always come in pairs, known as action-reaction force pairs.

8. Rock climbers pull their vertical rope ______ to move up.

1. Upwards
2. Downwards
3. Side way
4. None of the options

Answer: b) Downwards

Explanation: We can see the action-reaction pair in this example; rock climbers pull the rope down to climb up.

9. Gravitational force is a ______

1. Contact force
2. Non-contact force
3. Neither contact nor non-contact force
4. Semi contact force

Answer: b) Non-contact force

Explanation: Gravitational force is the best example of non-contact force.

10. Define net force.

Net force is defined as the vector sum of all forces acting on a body.

Practice Questions

1. State Newton’s third law of motion.
2. Explain action-reaction pairs with an example.
3. Give three examples of interaction force pairs.
4. What is conservation of momentum?
5. What is the formula for Newton’s laws of motion?

Watch the video and solve important questions in the chapter Force and Laws of Motion Class 9