Question

A 83.8 kg astronaut is working on the en- gines of a spaceship that is drifting through space with a constant velocity. The astronaut turns away to look at Earth and several sec- onds later is 39.6 m behind the ship, at rest relative to the spaceship. The only way to re- turn to the ship without a thruster is to throw a wrench directly away from the ship. The wrench has a mass of 0.608 kg, and the astro- naut throws the wrench with a speed of 17.9 m/s.
How long does it take the astronaut to rea