Problems: Developing Engineering Skills 157 is heated at constant pressure until the piston hits the stops. Heating then continues until the water is saturated vapor. Show the processes of the water in series on a sketch of the T-v diagram. For the overall process of the water, evaluate the work and heat transfer, each in kJ/kg. Kinetic and potential effects are negligible. 3.72 A piston-cylinder assembly contains 2 lb of water, initially at 100 lbf/in.2 and 400°F. The water undergoes two processes in series: a constant-pressure process followed by a constant- volume process. At the end of the constant-volume process, the temperature is 300°F and the water is a two-phase liquid-vapor mixture with a quality of 60%. Neglect kinetic and potential energy effects. (a) Sketch T-v and p-diagrams showing the key states and the processes. (b) Determine the work and heat transfer for each process, all in Btu. 3.73 A system consisting of 3 lb of water vapor in a piston- cylinder assembly, initially at 350°F and a volume of 71.7 ft³, is expanded in a constant-pressure process to a volume of 85.38 ft. The system then is compressed isothermally to a final volume of 28.2 ft. During the isothermal compression,