Dynamics then tells you why the object goes up, why the object goes down and why is it pulled down and so on.

而动力学则会告诉你为什么物体向上运动,为什么向下运动,为什么停下来,等等

耶鲁公开课 - 基础物理课程节选

We do some exercise, dips, pull-ups,

我们做一些运动，仰卧后撑，做引体向上。

圣莫妮卡的 DJ - SpeakingMax英语口语达人

Then he knows it's going to go up, it's going to curve, follow some kind of parabola, then his hands go there to receive it.

所以他就知道,这颗糖会先向上,再向下,沿着某条抛物线运动,然后他就能判断在哪里接住糖

耶鲁公开课 - 基础物理课程节选

It means, when you are accelerating upwards, as the elevator picks up speed, the reading on the spring will be more and you will feel heavy.

也就是说当你向上做加速运动时,就像电梯加速的时候,弹簧的读数会增大,你会觉得自己变重了

耶鲁公开课 - 基础物理课程节选

Now, what happens if the elevator is accelerating upwards with an acceleration a?

现在如果电梯向上以加速度 a 运动,会发生什么呢

耶鲁公开课 - 基础物理课程节选