Question

A man is attempting to push a chair across the floor with constant speed by exerting a force of 50 N. When will the chair exert a force of 50 N on the man?

1) only if the man and the chair are at rest
2) only if the man and the chair are accelerating
3) only if the man and the chair are moving with constant velocity
4) in all of the above cases

Answer 1

The chair will exert a force of 50 N on the man only if the man and the chair are moving with constant velocity.

Step-by-step explanation:

The correct answer is 3) only if the man and the chair are moving with constant velocity.

When the man exerts a force of 50 N to push the chair across the floor at a constant speed, the chair will exert an equal and opposite force of 50 N on the man. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. In this case, the action is the force exerted by the man, and the reaction is the force exerted by the chair.