A heat engine operates in a reversible cycle with the following steps:
(i) An ideal gas characterized by γ = 1.4 expands adiabatically, so that it cools from an initial temperature of 330°C to 30°C.
(ii) It is compressed isothermally until it reaches its initial volume.
(iii) It is then heated at constant volume until it reaches its initial temperature.
Calculate the efficiency of the cycle.
Compare your answer above with the Carnot efficiency that corresponds to these temperatures.
η_Carnot = 1 - T_c/T_h
The Attempt at a Solution
The answers are 0.30 and 60%. I know how to get the Carnot efficiency, but I'm not sure how to solve for the first answer. How do you find the efficiency with just 2 temperatures and a heat capacity ratio?