1. R-410a at 150 psia and 140 F is expanded in a piston/cylinder to 75 psia, 80 F in a reversible process. Find the sign for both the work and the heat transfer for this process.
2. A piston/cylinder receives R-410a at 75 psia and compresses it in a reversible adiabatic process to 300 psia, 160 F. Find the initial temperature.
3. A piston/cylinder contains 1 lbm water at 40 psia, 600 F, and it now cools to 280 F in an isobaric process. The heat goes into a heat engine that rejects heat to the ambient at 77 F, shown in Fig. P6.46, and the whole process is assumed reversible. Find the heat transfer out of the water and the work given out by the heat engine.
