So, it's a trivial matter, by looking at what is the weight and how far does it drop, to say OK, how much work is done by the paddle wheel.

好，让我们看看重物的质量,以及它下落的距离，就知道桨轮做了多少功。

麻省理工公开课 - 热力学与动力学课程节选

now I'm really fantastic at drawing this mechanical device, but you can imagine that dropping a weight can cause a paddle wheel to turn.

机械装置的时候,我真的很着迷，你可以想象,当重物掉落的时候会带动桨轮旋转。

麻省理工公开课 - 热力学与动力学课程节选

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