Answer:
259.62521 seconds
Step-by-step explanation:
 = Mass of astronaut = 87 kg
 = Mass of astronaut = 87 kg
 = Mass of wrench = 0.57 kg
 = Mass of wrench = 0.57 kg
 = Velocity of astronaut
 = Velocity of astronaut
 = Velocity of wrench = 22.4 m/s
 = Velocity of wrench = 22.4 m/s
Here, the linear momentum is conserved

Time = Distance / Speed

The time taken to reach the ship is 259.62521 seconds