Two people are riding inner tubes on an ice-covered (frictionless) lake. The first person has a mass of 65 kg and is travelling with a speed of 5.5 m/s. He collides head-on with the second person with a mass of 140 kg who is initially at rest. They bounce apart after the perfectly elastic collision. The final velocity of the first person is 2.1 m/s in the opposite direction to his initial direction.
(a) Are momentum and kinetic energy conserved for this system? Explain your answer.
(b) Determine the final velocity of the second person