Answer:

Complete question

Luis is trying to push a box of new soccer balls across the floor.

If the box is not moving, which of the following must be true?

A. The box is exerting a larger force on Luis than he is exerting on the box

B. There is another force acting on the box that balances Luis’s force.

C. Luis is applying a force that acts at a distance.

D. There is no force of friction acting on the box.

Explanation:

Using newton second law of motion

ΣF = ma

Now, for a body not to move when a force is acting on it means that the body is in equilibrium and acceleration a = 0

Therefore,

Fnet = 0

So, if he is applying a force F to push the box and the box is not moving then, there is an external force that is pushing the force back opposite the direction he his pushing and this force counterbalance is own force.

F—F’ = 0

F’ = F

So, F’ is the counter balance force and it is equal to the force applied by Luis

Or it might be frictional force, because if the static friction is not overcome, then, the body will not leave it’s state of rest. So if the fictional force is very high, then the box will not leave it rest position and we also know that frictional force opposes motion,

F—Fr=0

F = Fr

So using this explanation,.

The answer is B

B. There is another force acting on the box that balances Luis’s force.