Question

A girl is pushing a box towards the east direction. In which direction should her friend push the box so that it moves faster in the same direction?
(A) North
(B) South
(C) East
(D) West

Answer 1

In order to solve this question, we should know about force. Force is the external entity when applied on any object creates an acceleration and produces motion in the object. Force is a vector quantity, it has magnitude as well as direction and here we will examine the situation with the concept of force and then figure out the direction in which one should apply force to move the box faster.

Complete Step By Step Answer:
Since pushing a body simply means applying a force on a body in a definite direction. and when multiple forces act on a body we simply add them using vector law of addition to find net magnitude of force and its direction. More the net force on a body, the faster it will move. Now, coming to the question, when a girl pushes a box in the east direction the box will start to move in the east direction due to applied force and now to move it faster in the same direction one should apply more force but in the same direction so that its resultant force will be in the same direction. So, her friend must apply some force in the east direction to keep moving the box in the east direction but faster.
Hence, her friend must push the box in the direction of east to move the box faster, so correct option is (C) East.

Note:
It should be remembered that, applied force is directly proportional to the acceleration produced in the body $F \propto a$ so more the net force, more the acceleration, more the acceleration more fats a body will move and net force due to multiple forces acting on a body is always maximum if only if all the force acts in the same direction.