1. The problem statement, all variables and given/known data Hookes law: Calculate the work done by compressing a spring by x distance 2. Relevant equations W = Fd Ee = 1/2 k x^2 F = kx 3. The attempt at a solution I've found two solutions, but only one is correct. I'm confused why it's the second one. First formula I derived: W = Fd F = kx d = x Therefore W = kx^2 However, you can also use the elastic potential energy equation which is a modified version of the equation I made which is W = 1/2 k x^2 - 0 So, why is it the second equation and not the first one? The way I see it, they sort of both are valid. What is wrong with the first one? Work is force * distance, and that's exactly what I'm doing.