Suppose we slowly push the piston back to its original position in Figure 21.6, all the while maintaining a constant temperature in the gas.

(a) Over the time interval that includes the expansion and the compression of the gas, has any energy been converted?

(b) Does the entropy of the gas increase, stay the same, or decrease over that time interval?

(c) If we keep repeating the expansion and compression, is this device a steady device?

Transcribed Image Text:

Figure 21.6 A gas held at constant temperature in a cylinder fitted with a movable piston expands slowly as the load on the piston is diminished. Sand is removed slowly. T-TR T-TR Vi P P