Third Law of Motion - NEET Physics Questions
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Third Law of Motion

Question 1:

Which of the Following is Wrong about  “Action and Reaction pair”

1. Act on two different objects
2. Have equal magnitude
3. Have equal magnitude
4. Have resultant zero
View Answer

Action and Reaction forces cannot cancel each other to have zero resultant because they act on two different bodies

Question 2:

When a horse pulls a cart, the force that helps the horse to move forward is the force exerted by

1. the cart on the horse
2. the ground on the horse
3. the ground on the cart
4. the horse on the ground
View Answer

Horse applies force on earth at certain angle. In turn earth apply force on horse horizontal component of this force helps the horse and cart to move forward. 

Question 3:

In a general debate on topic “normal reaction and mg never form action and reaction pair” a number
of students  took part :-
(I) Navneet said – Action and reaction forces should be of same nature
(II) Anand said – Action and reaction forces act on two different bodies here, normal reaction and mg both are acting on the block.
(III) Meenakshi said – Action and Reaction forces balance each other. So, normal reaction and mg should be action and reaction pair.

Mark correct option as your judgement 

1. All are correct
2. Only III is correct
3. Both (I) & (II) are correct
4. All are incorrect
View Answer

The correct option is:

(II) Anand is correct.

Explanation:
Action and reaction forces act on two different bodies, as per Newton's third law. Normal reaction and gravitational force (mg) both act on the same block, so they cannot form an action-reaction pair.