Physics - Center of Mass Question with Solution | TestHub

As shown below, bob $A$ of a pendulum having massless string of length ' $R$ ' is released from $60^{\circ }$ to the vertical. It hits another bob $B$ of half the mass that is at rest on a friction less table in the center. Assuming elastic collision, the magnitude of the velocity of bob A after the collision will be (take g as acceleration due to gravity.)