Question

Two men, A and B , are loading identical boxes onto a truck. A lift his box straight up from the ground to the bed of the truck, whereas B slides his box up a rough ramp to the truck. Which statement is correct about the change in potential energy on the box-Earth system?
A.A and B change the potential by the same amount. B. A change more potential energy than B
C.B changes more potential energy than A D.None of those statements is necessarily true because the force of friction and the angle of the

Answer 1

A. A and B change the potential by the same amount.

Reason: gravitational potential energy depends only on the vertical displacement: ΔU = mgh. Both boxes end up at the same height, so the change in box–Earth potential energy is the same. Friction changes how much work the workers must do (more work for the ramp case), but it does not change the gravitational potential energy.