1. The problem statement, all variables and given/known data This isn't a homework question, just something I've been thinking about. If given a situation in which mass m is hung on a spring with constant k, I know you can set the spring force equal to the weight of the mass to find how far it stretches. Is there a way to find how far it stretches using energy equations? It seems like it should be doable, but I can't figure out how. 2. Relevant equations w = mg F = -kx ΔUg = mgh Us = kx2/2 3. The attempt at a solution As I said, setting mg = kx can solve for x. How do I do it with energy though? Ug = Us mgx = kx2/2 But now I get a different answer for x. What did I do wrong with the energy equations?