Two discs A and B are moving with their flat circular surface on a smooth horizontal surface. Mass, radius and velocity of the two discs are `- m_(A) = 2M, m_(B) = M, r_(A) = R, = 2R, v_(A) = v,` and `v_(B) = 2v`. The velocities of the two discs are oppositely directed so that they just cannot avoid collision and stick to each other (see figure)
(a) Find the angular speed of the composite system after collision
(b) Find loss in kinetic energy due to collision

Answer

(a) `omega = (2v)/(3R)`
(b) `kE_("loss") = Mv^(2)`