The discussion clarifies the concept of work in a pressure-volume (PV) diagram, specifically addressing why work can be negative during an isothermal process. It establishes that work is calculated using the integral ∫P.dV, where a leftward movement along the volume (V) axis indicates negative dV. The net work for a cycle is determined by the areas under the curve in the PV diagram, with the area from points a to c representing work done by the system and the area from c to b representing work done on the system. If the direction of the cycle is reversed, the net work becomes positive.
PREREQUISITESStudents of thermodynamics, physics educators, and anyone seeking to understand the principles of work in pressure-volume diagrams.
It is not to do with the direction around the loop but rather the direction along the V axis. Work is ∫P.dV. If it is going leftward along the V axis then dV is negative.lc99 said:
