A ring of radius `R` rolls without slipping on a rough horizontal surface with a constant velocity. The radius of curvature of the path followed by any particle of the ring at the highest point of its path will be :
.

Options

A. `R`
B. `2R`
C. `4R`
D. none of the above

Answer

C

Explanation

Radius of curvature `=(("velocity")^(2))/("Normal acceleration")`
Radius of curvature =`((2v)^(2))/((v^(2))/R)=4R`