Assuming that the box is moving when it is being pulled, Work is done on the box.
So work is the Force times the distance
W=Fd
But what is work actually ? When something moves due to force over some change in distance, it have energy.
But where does this energy come from ? Does it magically appear ? The energy comes from the applied force onto the box.
So the energy have been transferred. And it’s like that throughout the universe
Now to save time, I’ll just tell you the answer: kinetic energy
:)
