他们是迫于外界压力才做这件事的。

They did it in response to external pressures.

youdao

不过外界压力日增。

But the pressure is mounting.

youdao

我们决不向外界压力屈服。

We'll never yield to external pressure.

youdao

This piston is being brought out, so we expect 0 the work to be negative, negative. And we start o V2 ut with zero volume. We end up with a volume p2 of V2, and the external pressure is constant to p2.

所以我们可以想象功是负的,开始的时候体积是,最终的容积是,外界的压力恒为。

麻省理工公开课 - 热力学与动力学课程节选