Physics

Problem

A gas in a piston–cylinder assembly undergoes three consecutive steps: 1. At constant volume it absorbs

+250\,\text{J}

of energy by heating. 2. It is then compressed adiabatically so that

+120\,\text{J}

of work is done on the gas. 3. Finally, it expands at constant pressure, doing

40\,\text{J}

of work on the surroundings while releasing

-60\,\text{J}

of energy by heating. What is the net change in the internal energy

\Delta U_{\text{net}}

of the gas for the entire sequence? a)

+150\,\text{J}

+270\,\text{J}

+30\,\text{J}

+310\,\text{J}