So this is going to be review still again, and for those of you for whom it isn't review don't worry.

那么就当作是复习了,那些之前没有学过的同学也不用担心

耶鲁公开课 - 博弈论课程节选

There are many kinds of work. There's electrical work, take the motor, you plug it into the wall, electricity makes the fan go around, that's electrical work. There's magnetic work.

我们复习一下大一,学过的功的概念：,物体在力的作用下，运动了一段距离。

麻省理工公开课 - 热力学与动力学课程节选