A sphere is performing pure rolling as shown in figure. The radius of curvature of trajectory of point A in the shown portion is (OA = R/2)

A sphere is performing pure rolling as shown in figure. The radius of

1.	A sphere is performing pure rolling as shown in figure. The radius of curvature of trajectory of point A in the shown portion is (OA = R/2)
Answer» `9/4R` `R/2` `9/2R` `R/4` ANSWER :C