Two pounds of carbon dioxide (CO2) as an ideal gas executes a Carnot power cycle while operating between thermal reservoirs at 530 and 100oF. The pressures at the initial and final states of the isothermal expansion are 400 and 200 lbf/in2, respectively. The specific heat ratio is k = 1.24. Determine the thermal efficiency, the work for the isothermal expansion, in Btu, and the work for the adiabatic expansion, in Btu.