The diagram given below shows a ring rolling purely on a flat surface, what is the ratio of velocity of points A to point B?

√2:1 2:1 1:2 1:√2

√2:1

The velocity of point A =vo+ Rω = 2Rω , since in pure rolling vo = Rω. Velocity of point B = √ (v2o + R2ω2) = √ (2R2ω 2) =Rω√2. Thus, ratio of velocities = 2Rω/Rω√2 = √2:1.