Suppose the person pulling the string in Figure 21.13 does work \(W\) on the device immersed in a thermal reservoir \(\mathrm{R}\) at temperature \(T_{R}\).

(a) Do the energy and entropy of the reservoir increase, decrease, or stay the same?

(b) If the same experiment is repeated with the reservoir at a lower temperature, are the changes in the energy and entropy of the reservoir greater than, the same as, or smaller than in part \(a\) ?

Data from Figure 21.13

If thermal reservoir keeps system at constant temperature... system constitutes steady device. T=TK TR