In this cycle, air is first compressed in a piston-cylinder cylinder assembly in an adiabatic process. Heat is then added with the volume held constant to raise the pressure. Then it is expanded in an adiabatic process. Then heat is removed to bring the pressure back down to the original pressure. During these compression and expansion processes, the pressure-volume relationship can be approximated by PVn = constant where n is approximately 1.4. The initial volume of the cylinder is 1 m3 (a really big engine cylinder) and it is at one atmosphere of pressure. It is compressed to a volume of 0.1 m3. At this same volume, heat is added to increase the pressure to 50 atmospheres and then the air expands back to 1 m3. Then heat is removed to bring the pressure back down to 1 atmosphere with the volume held constant at 1 m3.
If 500 kJ of heat are removed from the cylinder after the expansion to bring the pressure back down to one atmosphere, what is the efficiency of this cycle?