What will I have to know? Yes?

我需要知道些什么请讲
Very good. That's all I wanted from you.

很好这是我希望你们告诉我的
We'll fill in the blanks but it's v^2 / R,

我们来填这个空格是 v^2 / R
and R is this quarter of a million miles,

R是 250000 英里
and v is the orbital velocity.

v 是轨道速度
You may not know the orbital velocity of the Moon

你们可能不知道月球的轨道速度
but you know it goes around every 28 days or something, right?

但你知道它大概每 28 天转一圈对吧
So, velocity is 2πR / 28 days.

所以速度大小就是 2πR 除以 28 天
Put it into seconds, you get some acceleration. Yes?

换算成秒你就得到了加速度请讲
Yes.

是的
Right, exactly.

是的就是这样
In fact, if it's not a circle

运动轨迹要不是个圆的话