A disc of radius R is rolling without sliding on a horizontal surface at a constant speed of `v`

(a) What is speed of points A and B on the vertical diameter of the disc ? Given `AB = (R)/(2)`
(b) After what time, for the first time, speed of point A becomes equal to present speed (i.e., the speed at the instant shown in the figure) of point B?

Answer

(a) `V_(A) = 2V, V_(B) = (3V)/(2)`
(b) `t = (2R)/(V) cos^(-1) ((3)/(4))`