79kg person jumps from a platform that is 100m above the water. He is attached by a bungee chord with sprint constant 40 N/m and length 35 m. Now he jumps off. How far is he above the water now when the chord has reached maximum elongation
F=ma, Ek= 1/2mv2 Ep=mgh...etc
The Attempt at a Solution
I'm kind of stuck.. I know it involves energy, but the maximum elongation of the chord confuses me.