7a.3Block 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 moves to right with speed of 2.0 m/s and block B moves to right with speed of 3.0 m/s.

(a) What is the momentum change for block A? [Answer: -6 kgm/s]

(b) What is the momentum change for block B? [Answer: 6 kgm/s]

(c) What is the momentum change for the system? [Answer: 0]

I have the answers, I just need a step by step explanation, please. Thank you