Consider an ideal gas whose entropy is given by
$$
S=\frac{n}{2}\left[\sigma+5 R \ln \frac{U}{n}+2 R \ln \frac{V}{n}\right],
$$
where $n=$ number of moles, $R=$ universal gas constant, $U=$ internal energy, $V=$ volume, and $\sigma=$ constant.
(a) Calculate $c_p$ and $c_v$, the specific heats at constant pressure and volume.
(b) An old and drafty house is initially in equilibrium with its surroundings at $32^{\circ} \mathrm{F}$. Three hours after turning on the furnace, the house is at a cozy $70^{\circ} \mathrm{F}$. Assuming that the air in the house is described by the above equation, show how the energy density (energy/volume) of the air inside the house compares at the two temperatures.