I have attempted a solution to the following problem: Block A is released from rest 0.

I have attempted a solution to the following problem:  Block A is released from rest 0.2 m vertically above a bumper on B and slides down a frictionless surface of B until A hits the bumper on the right end of B. Block A mass = 10 kg. Object B mass = 30 kg. B can roll freely on the ground. Find velocities of A and B immediately after impact with the bumper for two cases: (a) coefficient of restitution = 0, (b) coefficient of restitution = 0.7. ) See attached complete solution which includes a figure which shows block A before and after impact.  However, my answer for (b) does not match the textbook's (vA' = +1.201 m/s, vB' = +0.4 m/s) and I don't know why.  Perhaps I have an error.  Please review my process and calculations.  Note that I analyze the impulses that A and B apply to each other prior to impact to determine the initial velocity of B and then concluded, via conservation of momentum, that, for e=0, vA' = vB' = 0.  Also note that in (b), v' refers to the initial velocity and v'' refers to the final velocity.