To practice Problem-Solving Strategy 20.1 Heat Engines. Steam at a temperature TH = 255 ∘C and p = 1.00 atm enters a heat engine at an unknown flow rate. After passing through the heat engine, it is released at a temperature TC = 100 ∘C and p = 1.00 atm . The measured power output P of the engine is 460 J/s , and the exiting steam has a heat transfer rate of HC = 2000 J/s . Find the efficiency e of the engine and the molar flow rate n/t of steam through the engine. The constant pressure molar heat capacity Cp for steam is 37.47 J/(mol⋅K) .