1. The problem statement, all variables and given/known data I have to prove that the total energy of a spring mass system is equal to (1/2)k(delta L^2 + A^2) The spring is in three sates, equilibrium (I proved that already), maximally stretched, and maximally compressed. The spring is at equilibrium at a height h above ground level. delta L is the amount that the string stretches after the weight is added to the free spring. 2. Relevant equations EP = 1/2kx^2 K = 1/2kx^2 GE = mgh 3. The attempt at a solution For the spring maximally compressed : I have KE = 0 becuase it is not moving. EP = (1/2)k*(A-delta L)^2. when that is extended EP = 1/2*k*(A^2-2AdeltaL+deltaL^2). GE = m*g*(h-a). When all of these are added together it does NOT equal (1/2)k(delta L + A^2). I can't seem to find my error.