v We don't know what it is yet. In order to change this from a p to a V, you have to use the chain rule. So let's use the chain rule.

为了把这里的p变成,我们需要利用链式法则,好，让我们使用链式法则。

麻省理工公开课 - 热力学与动力学课程节选

Now, I hope you guys know that much calculus, that when you take a derivative of a function of a function, namely v square over 2 is a function of v, and v itself is a function of t, then the rule for taking the derivative is first take the v derivative of this object, then take the d by dt of t, which is this one.

我希望你们了解更多的微积分知识,当你对复合函数求导时,也就是说v^/2是关于v的函数,而v本身是关于t的函数,求导的法则应该是,第一步是这一部分对v求导,然后v再对t求导,得到这一部分

耶鲁公开课 - 基础物理课程节选