Unformatted text preview: fore both are irreversible. The magnitude of the irreversibility associated with each process can
be determined by calculating the total entropy change for each case. The total
entropy change for a heat transfer process involving two reservoirs (a source and
a sink) is the sum of the entropy changes of each reservoir since the two reservoirs form an adiabatic system.
Or do they? The problem statement gives the impression that the two reservoirs are in direct contact during the heat transfer process. But this cannot be
the case since the temperature at a point can have only one value, and thus it
cannot be 800 K on one side of the point of contact and 500 K on the other
side. In other words, the temperature function cannot have a jump discontinuity. Therefore, it is reasonable to assume that the two reservoirs are separated
by a partition through which the temperature drops from 800 K on one side to
500 K (or 750 K) on the other. Therefore, the entropy change of the partition
should also be considered when evaluating the total entro...
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