I'm selling tickets to a comedy show at the Times Square Art Center,

我在时代广场的艺术中心卖喜剧表演的门票，

街上的售票员 - SpeakingMax英语口语达人

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

If you want to write it as a vector equation, you want to write it as v square over r minus-- I want to say that it's pointing in the direction toward the center.

如果要写出矢量方程,就应该写成 -v^2 / r,也就是说,方向就向圆心

耶鲁公开课 - 基础物理课程节选