1. The problem statement, all variables and given/known data A mass is initially held in place at the top of a spring. When it is let go, it falls and compresses a spring. What is the maximum compression of the spring. 2. Relevant equations f=-kx 3. The attempt at a solution I know the solution is to equate mg and kx to find x. However, it doesn't make sense when I try it using energy equations. If you set 1/2kx^2 to mgh (where h = x), then the answer you get for x is 2 times the answer you get doing it the proper way. Does anybody know why?