I have shown you yesterday that the speed of the particle as it goes around the circle is this .

我昨天讲过,质点做圆周运动的速率等于这个

耶鲁公开课 - 基础物理课程节选

I'm asking what's the tangential speed as it moves along the circle?

它在做圆周运动时,切向速度是多少

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