An engine operates with 1 mol of an ideal gas for which R Cv = 3/2R and R Cp = 5/2p = as its working substance. The cycle begins at P1 = 1 atm and V1 = 24.6 L. The gas is heated at constant volume to P2 = 2 atm. It then expands at constant pressure until V2 = 49.2 L. During these two steps, heat is absorbed by the gas. The gas is then cooled at constant volume until its pressure is again 1 atm. It is then compressed at constant pressure to its original state. During the last two steps, heat is rejected by the gas. All the steps are quasi-static and reversible.

(a) Show this cycle on a PV diagram. Find the work done, the heat added, and the change in the internal energy of the gas for each step of the cycle.

(b) Find the efficiency of the cycle.