A softball of mass 0.220 kilogram that is moving with a speed of 6.0 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward it is found that the incoming ball has bounced backward with a speed of 4.3 m/s.
(a) Find the velocity of the target ball after the collision.
(b) Determine the mass of the target ball.