A cyclic equilibrium process in n moles of an ideal gas with cV = 2.5R is formed of three sub-processes:
a → b is a constant pressure doubling of the volume; b → c is at constant volume with decreasing pressure;c → a is adiabatic.
Assume that Vb = Vc = 2Va.
(a) Sketch the process on a PV diagram.
(b) Find the heat absorbed in sub-process a → b in terms of Ta, n, and R.
(c) Find the heat rejected in sub-process b → c in terms of Ta, n, and R.
(d) Find the energy efficiency of the cycle. Give a numerical answer.