1) Given & Find: a) R-134a at T = 60oC and v = 0.072 m3/kg. Find P and h.
b) Ammonia at P = 8 bar and v = 0.005 m3/kg. Find T and u.
c) R-22 at T = -10oC and u = 200 kJ/kg. Find P and v.
2) Given: R-134a is compressed with no heat transfer in a piston-cylinder assembly from 30 lbf/in2, 20oF to 160 lbf/in2. The mass of refrigerant is 0.04 lbm. For the refrigerant as the system, W = -0.56 Btu. Kinetic and potential energy changes may be neglected.
Find: The final temperature (oF).
3) Given: Saturated water vapor is contained in a closed rigid tank. The water is cooled to a temperature of 110oC. At this temperature the masses of saturated vapor and liquid are each 1000 kg.
Find: The heat transfer for the process (kJ).
4) Given: 0.5 kg of R-22 is contained in a piston-cylinder assembly, initially saturated vapor at 5 bar. The refrigerant undergoes a process for which the pressure-specific volume relationship is Pv = C to a final pressure of 20 bar. Kinetic and potential energy effects can be neglected.
Find: a) Work (kJ) and b) heat transfer (kJ) for the process.
5) Given: A gallon of milk at 68oF is placed in a refrigerator. Energy is removed from the milk at a constant rate of 0.08 Btu/s a the milk cools. Specific heat, cp,milk = 0.94 Btu/lbmoR and density, rmilk = 64 lbm/ft3.
Find: How many minutes will it take for the milk to cool to 48oF? How many minutes to cool another 10oF to 38oF?