A Carnot engine operating in reverse as a heat pump moves heat from a cold reservoir at 5°C to a warmer one at 25°C.
a. What is the efficiency of a Carnot engine operating between these two temperatures?
b. If the Carnot heat pump releases 200 J of heat into the higher-temperature reservoir in each cycle, how much work must be provided in each cycle?
c. How much heat is removed from the 5°C reservoir in each cycle?
d. The performance of a refrigerator or heat pump is described by a “coefficient of performance” defined as K = Qc /W. What is the coefficient of performance for our Carnot heat pump?
e. Are the temperatures used in this example appropriate to the application of a heat pump for home heating? Explain.