You put a chunk of wood on a table and you try to move it at constant speed.

你把一大块木头放在桌子上,试着让它匀速运动

耶鲁公开课 - 基础物理课程节选

Whenever you see a particle moving in a circle, even if it's at a constant speed, it has an acceleration, v square over r directed towards the center.

只要看到质点做圆周运动,即使是匀速圆周运动,也存在一个加速度,大小为 v^2 / r,方向指向圆心

耶鲁公开课 - 基础物理课程节选

And the relationship that he put forth is that the momentum is equal to Planck's constant times nu divided by the speed of light, or it's often more useful for us to think about it in terms of wavelength.

爱因斯坦提出的关系式是,动量等于普朗克常数,乘以υ除以光速，或者用波长来表示,通常更容易让我们想明白。

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