Find final speed of the astronaut after throwing the tank

[b40677]

A 64.1 kg astronaut is on a space walk when the tether line to the shuttle breaks. The astronaut is able to throw a 11.0 kg oxygen tank in a direction away from the shuttle with a speed of 11.7 m/s propelling the astronaut back to the shuttle. Assuming the astronaut starts from rest, find final speed of the astronaut after throwing the tank. Answer in units of m/s

 

[mezarashi]

What principle do you think you should apply?

 

[Mk]

The astronaut is able to throw a 11.0 kg oxygen tank in a direction away from the shuttle with a speed of 11.7 m/s

Damn that's fast! Are you sure its not like 1.17 m/s or is the question just stupid?

 

[asdf1]

ok here you go

use: Conservation of momentum

mass of oxygen tank X speed of oxygen tank = mass of astronaut X speed of astronaut