A power cycle boasts to have a thermal efficiency of 40%, while the engine operates between hot and cold thermal reservoirs. The cold reservoir is maintained at 300 K, and the temperature of the hot reservoir is (a) 600 K, (b) 500 K and (c) 400 K. Is the claim of 40% thermal efficiency valid for each of these cases?

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.