Thirty-six grams of air in a piston-cylinder assembly undergo a Stirling cycle with a compression ratio of six. At the beginning of the isothermal compression, the pressure and volume are 1 bar and 0.03m3, respectively. The temperature during the isothermal expansion is 1000 K. Assuming the ideal gas model and ignoring kinetic and potential energy effects, determine a. the net work, in kJ. b. the thermal efficiency.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.