Задача 20694.

The heat engine operates in a closed loop, consisting of two isochors and two isobars. To determine the efficiency of a heat engine, if the pressure and volume changes in a cycle of 2 times. Working the body considered diatomic gas.

Detailed solution with a short recording conditions, laws and formulas used in the decision, the withdrawal of the calculation formula and the answer.
If you have any questions about the decision to write. I try to help.