Now you could do a similar sort of thing, but instead of having a candle, you have a paddle wheel, and the paddle wheel is spun by a weight that's dropping from here to here.

那接下来可以做一件类似的事，但不再是蜡烛，我们将它换成一个桨轮，桨轮末端拴一个重物,它可以从这掉落到这。

麻省理工公开课 - 热力学与动力学课程节选