Aman jumps off a bridge 80 metres above a river below. his feet are tied by a bungee rope that is 40 metres long when not stretched. at the bottom, his head just touches the water. use calculations based on energy to work out where he will finally come to rest when he stops bouncing. ignore the man's height.

In the winter, in order to keep the classroom steadily at 68 f before 10 pm, heating with an average rate of 42,000 btu/hr is provided. assume the outdoor temperature maintains at 32°f, determine the electrical power (kw) required to (a) operate a reversible heat pump (b) operate a real heat pump with a cop (7) of 4.5 and (c) operate an electrical-resistance heater.