Thermodynamics (Physics)

[figure] Using the given P-V diagram, the work done by an ideal gas along the path ABCD is :

1. 3P0 V0
2. -3P0 V0
3. -4P0 V0
4. 4P0 V0

Answer

(2) -3P0 V0

Solution

Work = P dV = signed area under the path: positive on expansion (A to B), zero at constant volume (B to C), negative on compression (C to D).

[figure]

WAB=P0(3V0-2V0)=+P0V0, WBC=0, WCD=2P0(V0-3V0)=-4P0V0

W=-3P0V0

Answer: (2)