Practical steam engines utilize 475°C steam, which is later exhausted at 300°C. Explicitly show how you follow the steps in the Problem-Solving Strategy for thermodynamics found on pages 361-2 when answering the questions below. (Do this on paper. Your instructor may ask you to turn in this work.)
(a) What is the maximum efficiency that such a heat engine can have?
%
(b) Since 300°C steam is still quite hot, a second steam engine is sometimes operated using the exhaust of the first. What is the maximum efficiency of the second engine if its exhaust has a temperature of 150°C?
%
(c) What is the overall efficiency of the two engines?
%
(d) Show that this is the same efficiency as a single Carnot engine operating between 475°C and 150°C.