1. An ice chest is maintained at 0 degrees Celsius by ice placed in it. The chest is cubical with each inside wall having an area of 1200cm^2 and a thickness of 4cm. Each wall is made of foam plastic with k= 1.3X10^-4 cal/cm/s/C. How much ice will melt in the chest in an hour when the outside temperature is 24 degrees Celsius?

2. How many tons of refrigeration would be needed to change .1m^3 of water to ice (all at 0 degrees Celsius) in a time of 1 hour?

3. A certain heat pump uses 1000W and delivers heat at a rate of 600 cal/s.

a) How many calories of heat does the pump extract each second from the outside?

b) What is its coefficient of performance?