posted by Mike
The engine has an efficiency e1. The engine takes input heat Qh from a hot reservoir and delivers work W1. The heat rejected by this engine is used as input heat for a second engine, which has an efficiency e2 and delivers work W2. The overall efficiency of the two-engine device is the total wor kdfelivered (W1 + W2) divided by the input heat Qh. Find an expression for the overall efficiency in terms of e1 and e2.