a 123 kg man space finds himself 60 m away from his space ship and wants to get back. he holds a 2kg space gun which fires 5.00g bullet at a rate of 1500m/s. if he fires a single bullet in a direction directly away from the spaceship, how long would it take the man to arrive back to his ship in.

recoil of gun is 0=2vg +.005*1500
vg=-3.75

please help. i just don't know where to go after i get the recoil of gun

2 answers

Get the recoil velocity of the gun and man together. You did the problem incorrectly. The gun does not recoil all by itself. It is held.

(123 + 2)Vr = 0.005 * 1500
Vr = 0.06 m/s

Then divide the separation distance (60 m) by that velocity, to get the required time.
60 m/0.06 m/s = ___seconds = ___ minutes
thank you so much!