Prob. $2$ Considering a human body a powerplant, please identify the relative variables for energy and entropy analyses of a man riding a bicycle. $(10\%).$

Prob. $3$ For a pure, simple compressible system $c,$ and $c_p$ are defined by $c_v=(\frac{\text{d}\text{e}\text{l}\text{u}}{\text{d}\text{e}\text{l}\text{T}}{)}_v$ and $c_p=(\frac{\text{d}\text{e}\text{l}\text{h}}{\text{d}\text{e}\text{l}\text{T}}{)}_p,$ respectively. Please prove that $c_p$ is always greater than $c_v.(15\%)$