A finite hot reservoir at 600 K can supply exactly 5.0 kJ of thermal energy. The only available cold sink is the ambient environment at 300 K.
A student considers using a heat engine to convert part of this 5.0 kJ into mechanical work.
(a) Calculate the maximum possible work that any heat engine could deliver when the entire 5.0 kJ of energy is transferred reversibly from the 600 K reservoir to the 300 K environment.
(b) Before the engine can be connected, 1.0 kJ of the 5.0 kJ is accidentally lost as heat directly to the 300 K environment. The remaining 4.0 kJ is still available at 600 K. Determine the new maximum work that can now be obtained.
(c) Compute the change in entropy of the universe associated with the accidental 1.0 kJ heat leak described in part (b).
(d) Compare your answers to parts (a) and (b). Explain how the entropy change found in part (c) accounts for the reduction in the maximum obtainable work.