Systems that are colder than their environment have positive energy. Suppose a quantity of monatomic gas originally at ambient temperature and pressure (T₀, p₀) is adiabatically and reversibly expanded until its temperature has dropped to T. Compute its energy from eq. (36.25)

and show that it is positive. How can this gas do useful work?

Transcribed Image Text:

B = Max {Wuseful} = (U – Uo) + po(V – Vo) – To(S - So) |