1. The problem statement, all variables and given/known data A block of mass 250 g is kept on a vertical spring with spring constant 100N/m fixed from below. The spring is now compressed to have a length 10 cm shorter than its natural length and is released. How high does the block rise?g = 10m/s 2. Relevant equations E=½kx² and other basic equations 3. The attempt at a solution So I found out initial energy imparted, $$E_1 = ½kx² = 0.5 J$$ then equated to change in potential and new spring energy. $$E_2 = mgh + ½k(x-h)²$$ where h is the height required solving E₁= E₂, I get an awkward answer. the answer given is 20 cm. How?