Question

A 63 kg astronaut on a spacewalk when his line breaks. He throws a 10 kg o2 tank away from the ship with a v=12 m/s. This propels him back to the ship. Assume his v1=0; what is his v2?

Answer 1

momentum east = momentum west because it was all zero before the toss. :)
63 v2 = 10 * 12