Newton's Third Law of Motion

Ten coins each of mass $10 \mathrm{g}$ are placed one above the other. The reaction force exerted by $7\mathrm{th}$ coin from the bottom on the $8\mathrm{th}$ coin is _____.

($g=10 \mathrm{m}/{\mathrm{s}}^2$)

Consider the situation shown in figure. Masses of both the block and the pulley is $m$. Assume that string and spring are light, the  elongation of the spring at equilibrium is

The frictional force is an example of internal force.

Magnetic force is example of _____ force.

Which one of given force is not example of internal force?

Which of the given force is not external force?

Can a single isolated force exist in nature? Explain your answer.

Why is it not possible to push a car from inside?

Two bodies A and B of masses $5 \mathrm{kg}$ and $10 \mathrm{kg}$ in contact with each other rest on a table against a rigid wall as shown in the figure. The coefficient of friction between the bodies and the table is $0.15$. A force of $200 \mathrm{N}$ is applied horizontally to A. What are:

(a) the reaction of the partition?
(b) the action-reaction forces between A and B?

What happens when the wall is removed? Does the answer to (b) change, when the bodies are in motion? Ignore the difference between ${\mu }_s$ and ${\mu }_k$.

Action and reaction _____ act on the same body.

(Choose from: can/cannot)

Newton’s third law of motion can be derived as a second special case of Newton’s _____ law of motion.

Which theory of motivation emphasizes the role of external rewards and punishments?

What role does 'reinforcement' play in the learning process?

Assertion: Nuclear force doesn't obey Newton's third law.

Reason: Nuclear force is not a central force.

Assertion: The third law of motion concludes that the forces occur in pairs of action and reaction.

Reason: The action force is more than the reaction force.

Assertion: Newton's third law is not applicable for nuclear forces.

Reason: Nuclear forces are short-ranged.