What that means is, if you know the velocity of the given time and you know the initial velocity, you know what time it is.

这个方程的意义是,如果你知道某个给定时刻的速度,并且知道初速度,你就能知道运动的时间

耶鲁公开课 - 基础物理课程节选

But before you even do that, I want to define for you an important concept, which is the velocity at a given time, v .

但在这之前,我要给你们定义一个重要的概念,也就是给定时刻的瞬时速度v

耶鲁公开课 - 基础物理课程节选

If you want to know how fast it's moving at a given time, if you want to know the velocity, I just take the derivative of this answer, which is 10-10t.

如果你想知道它在给定时刻的运动有多快,如果你想知道它的速度,我只要对这个式子求导,得到10-10t

耶鲁公开课 - 基础物理课程节选