Two astro nauts at rest face each other in space. One, who has mass m1,throws a ball of mb to the other. whose mass is m2. The second astro naut catches the ball and throws it back to the first astronaut. Following each throw, the ball has a speed of V (m/s )relative to the thrower. After each has made one throw and one catch,
(a) How fast are the astronauts moving?
(b) How much has the two astronaut system's kinetic energy changed and where did this energy come from?