1. A mass of 20 kg travels at 7m/s and collides with a mass of 12kg travelling 20m/s in the opposite direction along the same line. The coefficient of restitution is 0.7. Determine the velocities after collision. (-10.21 m/s, 8.687m/s) 2. A mass of 10 kg travels at 8m/s and collides with a mass of 20kg travelling 4m/s in the same direction along the same line. The coefficient of restitution is 0.8. Determine the velocities after collision. (3.2 m/s, 6.4m/s) 3. A mass of 4 kg moves at 5m/s gold collides with a mass of 2kg moving at 5m/s in the opposite direction along the same line. The coefficient of restitution is 0.7. Determine the velocities after collision. (-0.67m/s, 6.33m/s) 4. Ball A of mass 1 kg as shown in Figure QA2 (a) moves with a velocity of 2 m/s and hits ball B of mass 2 kg which is at rest. Ball A comes to rest after hitting ball B. Determine . velocity of Ball B after impact ii. coefficient of restitution (1 m/s. 0.5)