An astronaut, stranded in space 11.0 m from his spacecraft and rest relative to it, has a mass (including equipment) of 125 kg. Because among his equipment he has a 100 W light source that forms a directed beam, he considers using the beam as a photon rocket to propel himself continuously toward the spacecraft.
Suppose, instead, that he decides to throw the light source away in a direction opposite the spacecraft. If the mass of the light source is 3.00 kg and, after being thrown, moves at 12.0 m/s relative to the recoiling astronaut, how long does it take for the astronaut to reach the spacecraft?