A 61.0 kg bungee-cord jumper is on a bridge 45.0 m above a river. The elastic bungee cord has a relaxed length of L = 25.0 m. Assume that the cord obeys Hooke’s law, with a spring constant of 160 N/m. .lf the jumper stops before reaching the water, what is the height h of her feet above the water at her lowest point?
SOLUTION: Shows the jumper at the lowest point, with her feet at height h and with the cord stretched by distance d from its relaxed length. If we knew d, we could find h.
Forces: The gravitational force does work on the jumper throughout her fall. Once the bungee cord becomes taut, the spring like force from it does work on her. transferring energy to elastic potential energy of the cord.