7a.2 Block A of mass 2.0 kg slides into block B of mass 2.0 kg. Before collision, block A moves to right with speed of 5.0 m/s, and block B is stationary. After collision, block A is stationary and block B moves to right with speed of 5.0 m/s. (a) What is the initial momentum for the system? [Answer: 10 kg.m/s] (b) What is the final momentum for the system? [Answer: 10 kg:m/s] (c) What is the momentum change for the system? [Answer: 0]