Three cricket balls have masses of 4 kg, 6 kg, and 8 kg, respectively. The ball A has a velocity of 12 m/s while the other balls are initially at rest. The ball A collides with the ball B and rebounds in the opposite direction with a velocity of 7 m/s. (a) Calculate the momentum of ball A before the first collision. (b) Calculate the velocity of ball B after the first collision. Ball B now hits ball C (which has gum on it) and sticks to it. (c) What is the velocity of the balls after this second collision