Astronauts are playing baseball on the International Space Station. One astronaut with a mass of 50.0 kg, initially at rest, hits a baseball with a bat. The baseball was initially moving toward the astronaut at 35.0 m/s, and after being hit, travels back in the same direction with a speed of 45.0 m/s. The mass of a baseball is 0.14 kg. What is the recoil velocity of the astronaut?