1. The problem statement, all variables and given/known data A 70 kg bungee jumper leaps off a bridge. She is tied to a 12 m long bungee cord and falls a total of 31 m. Calculate: a) the spring constant of the bungee b) the maximum acceleration experience by the jumper 2. Relevant equations F = kx Eg = Ee where g is gravitational potential energy and e is elastic energy 3. The attempt at a solution at her maximum stretch, force of the "spring"/bungee Fs = Fg = mg x= 31 - 12 = 19 k= F/x = mg/x k = 70 (9.81) / 19 k= 36.14 but this number didn't seem right so i did: let height be zero at maximum stretch Eg = Ee mgh = 1/2kx^2 70(9.81)(31) = 1/2k(19)^2 k = 117.9 both methods make perfect sense to me, but the spring constants are different so i must have missed something. what did i do wrong/which method is correct? and how can i find her maximum acceleration?