For example, no matter how much a dancer wishes to leap off the floor and then start turning, the law ofconservation of angular momentum absolutely prevents such a movement.
例如，无论一个舞者多么想要跳离地板，然后开始旋转，角动量守恒定律绝对阻止这样的动作。
3
You see it on the general exams for physics, and it's simply a matterofconservation of mechanical energy.