- #1

MexChemE

- 237

- 55

I am currently taking Thermodynamics I, and I have trouble figuring out the expression: [tex]W = \int_{V_1}^{V_2} PdV[/tex] I suppose pressure is being treated like a constant in the above equation. If so, if we integrate we would get this expression: [itex]W = P(V_2-V_1)[/itex], right? But then I read in HyperPhysics that we express work as an integral when pressure varies too, so, wouldn't we need an integral of two variables?

I know we express work as an integral because it is the area under the PV curve, but as you can see I'm currently lost between concepts. I hope my question makes sense. Thanks in advance!