A ball of 0.238 kg is moving to the right having a speed of 6.50 m/s if it collides head-on with a stationary ball. After this collision, which is elastic, the incoming ball travels to the left having a speed of around 4.90 m/s.
(i) Determine the speed of the ball which was primarily stationary after the collision? (Take the positive direction as to the right.)
(ii) Determine the mass of the ball?