Two identical objects, A and B, are thermally and mechanicallyisolated from the rest of the world. Their initial temperatures areTA > TB. Each object has heat capacity C (the same for bothobjects) which is independent of temperature.
(a) Suppose the objects are placed in thermal contact and allowedto come to thermal equilibrium. What is their final temperature?How much entropy is created in this process? How much work is doneon the outside world in this process?
(b) Instead, suppose objects A (temperature TA) and B(temperature TB < TA) are used as the high and low temperatureheat reservoirs of a heat engine. The engine extracts energy fromobject A (lowering its temperature), does work on the outsideworld, and dumps waste heat to object B (raising its temperature).When the temperatures of A and B are the same, the heat engine isin the same state as it started and the process is finished.Suppose this heat engine is the most efficient heat enginepossible. In other words, it performs the maximum work possible.What is the final temperature of the objects? How much entropy iscreated in this process? How much work is done on the outside worldin this process?
