1. How much kinetic energy did 93.9-kg Usain Bolt have when he broke the Olympic 100-m dash record with a speed of 10.25 m/s?
2. A 70.0 kg stuntman is attached to a bungee cord. He is standing on a ledge that is 50 m high. How much gravitational potential energy does he have?
3. The stuntman jumps off the ledge and bobs up and down for a while. When he finally stops, the cord is stretched 29 m. If the spring constant of the bungee cord is 71.8 N/m, how much elastic potential energy does the stuntman have?