Air is compressed from an initial temperature of 20 °C and pressure of 100 kPa to a final pressure of 1000 kPa. The isentropic efficiency of the compressor is 0.85. Find the exit temperature of the air and the specific work for the compressor. Assume variable specific heats.
Air is expanded in an adiabatic nozzle from an initial temperature of 800 °F and pressure of 150 psia to a final pressure of 20 psia. The isentropic efficiency of the nozzle is 0.95. Determine the exit velocity and exit temperature of the air. Assume constant specific heats.
A heat pump is designed to deliver 48000 BTU/hr into a residence and operates with a COP of 4.0. The inside of the house is maintained at 75 °F when the outside temperature is 15 °F. Determine the entropy generated by this device.
Ten kg of water is in a closed rigid container with a volume of 0.73 m3 and a temperature of 1000 °C. Determine the entropy generated as the temperature is reduced to 200 °C by transferring heat to a 20 °C environment.