Question

As a person pushes a box across a floor, the energy from the person’s moving arm is transferred to the box, and the box and the floor become warm. During this process, what happens to energy?

It is increased.
It is conserved.
It is decreased.
It is created.

Answer 1

It is conserved. The person does work on the box, converting mechanical energy from the moving arm into thermal energy (and a little kinetic energy of the box); total energy stays the same but changes form.