R And the track has a radius R, and at this moment in time the angle equals theta, and here is the object.

轨道半径是，在这个时刻,角度等于θ,这是物体。

youdao

So half the track is about 2.5meters, so the angle theta maximum - is approximately 2.5 meters-- - which is half the length of the track-- 115- divided by 115 and that is an extremely small angle.

它的一半是2。5米，因此角度θ的最大值,大约是2。5米-,也就是轨道的一半-,除以5,它实在是个小角度。

youdao

Let this be the angle d theta so it moves in a short amount of time over an angle d theta dS and the arc here is dS, R and the radius is R.

这是角度dθ,它运动了一会儿,运动过角度dθ,弧度是，半径是。

youdao