(a) Find the work done by the engine during each of the four steps and the net work done for the cycle. 

(b) If the heat input per cycle is 2770 J, what is the efficiency of the engine? 

(c) Compare the efficiency to that of an ideal engine using the same reservoirs.

The PV diagram shown is for a heat engine that uses 1.000 mol of a diatomic ideal gas as its working substance. In the constant-temperature processes A and C, the gas is in contact with reservoirs at temperatures 373 K and 273 K, respectively. In constantvolume process B, the gas temperature decreases as heat flows into the cold reservoir. In constant-volume process D, the gas temperature increases as heat flows from the hot reservoir.