For every action, there is an equal and opposite reaction.

Here's how it applies to your scenario:

* Action: You apply a force to the box (let's say you push it to the right).

* Reaction: The box, in turn, exerts an equal and opposite force on you (pushing you to the left).

Why does this happen?

Forces always occur in pairs. When you interact with an object, you are not just acting on it, but it is also acting back on you. The forces are equal in magnitude (strength) but opposite in direction.

Example:

If you push a box with 10 Newtons of force to the right, the box simultaneously pushes back on you with 10 Newtons of force to the left.

Important Note: These forces act on different objects. The force you apply acts on the box, and the force the box exerts acts on you.