申論題

5. (20 points) From electromagnetism it has been shown that the electromagnetic pressure exerted on the walls of a container of volume Vis related to the internal energy U through P=U/3V. With the assumption that: (I) the entropy of the system S(U,V) is a state function and (2) The energy density is related to temperature through UIV=AT² (where A and   λ  are constants), please show that λ=4. (Hint: Start from the law of thermodynamics and express