Now remember, we went through before how it's a state function but to calculate it, you'd need to find a reversible path, along which you can figure this out.

请记住，我们不需要知道它是怎样的一个态函数,只计算就可以了，你需要找到一条可逆路径，沿着这条路径就能算得这个结果。

麻省理工公开课 - 热力学与动力学课程节选

I'm going from V2 to V2 dv - what do you think this integral is? Right, W1 so this is easy part, zero here.

这样才保证了过程的可逆性,下面来计算，路径1的功。

麻省理工公开课 - 热力学与动力学课程节选

Reversible. Reversible means that if I looked at dw it's minus p reversible.

接下来是“可逆“,他说明当计算dw=-PextdV时。

麻省理工公开课 - 热力学与动力学课程节选