首先，我用了机械能，守恒定律-，这里没有摩擦力-，我会向你们展示，这，和功能定理完全一致，现在你会怎么做呢？

I used first the conservation - of mechanical energy — there was no friction — and then I showed you that it's completely consistent with the work-energy theorem, so what would you do now?

youdao

先学规则，即定理，运行的次序，牛顿定律-然后在章节的最后列一张问题列表。

Learn the rules first - the theorems, the order of operations, Newton's laws - then make a run at the problem list at the end of the chapter.

youdao

所以你也可以用，功能定理，或者是机械能，守恒定律。

And so you could have used the work-energy theorem or you can use the conservation of mechanical energy.

youdao