A heat engine using a monatomic gas follows the cycle shown in the $\backslash ($ p V $\backslash )$ diagram.

The gas starts out at point $1$ with a volume of $\backslash ($ V$\_\{1\}=233\backslash$mathrm$\{$~cm$\}^\{3\}\backslash ),$ a pressure of $\backslash ($ p$\_\{1\}=235\backslash$mathrm$\{$kPa$\}\backslash ),$ and a temperature of $287$ K $.$

The gas is held at a constant volume while it is heated until its temperature reaches $395$ K $($point $2).$

The gas is then allowed to expand adiabatically until its pressure is again $235$ kPa $($point $3).$

The gas is maintained at this pressure while it is cooled back to its original temperature of $287$ K $($point $1$ again$).$