1. The problem statement, all variables and given/known data A block A of mass MA = 1 kg is kept on a smooth horizontal surface and attached by a light thread to another block B of mass MB=2 kg .Block B is resting on ground and thread and pulley are massless and frictionless.A bullet of mass m 0.25 kg moving horizontally with velocity of u=200m/s penetrates through the block and comes out with a velocity of 100m/s.Find the height through which the block B will rise. Ans :5.21m 2. Relevant equations 3. The attempt at a solution When bullet penetrates through block A ,an impulsive force P acts on it. ∫Pdt = 0.25(200-100) = 25Ns Considering block A,let the impulsive tension be T ∫Pdt - ∫Tdt = 1(vA) Considering block B , ∫Tdt = 2vB I guess I am missing something ,is it vA = vB because of inextensibility of the string connecting the masses? But that doesn't give correct answer . I would be grateful if somebody could help me with the problem.