申論題

3.A heat engine operates between two reservoirs at T₂ = 500 K and T₁ = 300 K. It takes in 1000 J of energy from the higher-temperature reservoir and performs 250 J of work in one cycle. Find (a) the entropy change of the Universe △S_U, for this process and (b) the work Wthat could have been done by an ideal Carnot engine operating between these two reservoirs. (c) Show that the difference between the amounts of work done in parts (a) and (b) is T₁ △S_U. (15%)