The transition curve of 6th power function is a higher quality of transition curve in theory and practice. It is also suitable for use to a small radius circle curve as a transition curve.

理论和实践证明，六次代数式缓和曲线是一种质量较高的缓和曲线，它适用于作小半径圆曲线的过渡曲线。

youdao

That means, it can only be rattling around in a circle of radius R.

也就是说它只能,限制在一个半径为 R 的圆上运动

耶鲁公开课 - 基础物理课程节选

So we know it's moving on a circle of radius r.

因此这个质点始终在做半径为 r 的圆周运动

耶鲁公开课 - 基础物理课程节选

In Navevo's case the data will be used to flash a warning symbol on its sat-nav maps when a driver approaches a "warning zone" with a 50m (164ft) radius circle drawn around the area.

BBC: Navevo sat-nav offers cyclist alerts to lorry drivers