In a problem using energy considerations to solve for the speed of a ball thrown from the top of a building when it strikes the ground below,where should the potential energy have its zero value?
A)It should be at the level from where the ball is thrown.
B)It should be at the ground level where the ball hits.
C)It should be slightly below ground level so the potential energy is always positive.
D)It doesn't matter since only differences in potential energy matter in solutions.

Question

Quizplus · Accepted Answer

The choice of the zero level for potential energy is arbitrary in physics problems because only changes in potential energy are physically meaningful. What matters is the difference in potential energy between two points, not the absolute values. Therefore, any of these choices could be used without affecting the outcome of the problem, as long as the calculations are consistent with the chosen reference point.

In a Problem Using Energy Considerations to Solve for the Speed