**1. The problem statement, all variables and given/known data**

Suppose you lift a heavy weight from the floor to high over your head and let it fall back to the floor. An observer says you did no work because it wound up in its original position. You disagree. Who’s right?

**2. Relevant equations**

W = F*d

**3. The attempt at a solution**

Work is equal to force * distance, or in other words, the amount of force exerted over a certain distance. Work is also a scalar quantity, which makes the direction irrelevant to the problem (there are no negative or positive signs indicating the direction). All scalars are treated as positive values. Although the weight winds up in the same position, work is still done. Therefore, the total amount of work done is equal to the weight of the weight multiplied by the distance it is lifted up, in addition to when it is allowed to fall back to the floor. However, when it is lifted up, the person lifting the object is doing work. When it is left to fall, the person is no longer doing work and gravity does work pulling the object back to the ground.