# outer space question

by Mike667
Tags: outer, space
 P: 14 1. The problem statement, all variables and given/known data A 63 kg astronaut at rest in space throws a 10 kg oxygen tank with a speed of 12 m/s. What is the velocity of the astronaut immediately after throwing the tank? Which formula would I use to solve this? Thanks in advance.
HW Helper
P: 2,884
 Quote by Mike667 1. The problem statement, all variables and given/known data A 63 kg astronaut at rest in space throws a 10 kg oxygen tank with a speed of 12 m/s. What is the velocity of the astronaut immediately after throwing the tank? Which formula would I use to solve this? Thanks in advance.
Conservation of momentum. Here, the total momentum before was zero. so th etotal momentum after will be zero.
 P: 14 Yes, thats what i was thinking. thanks again.
P: 14

## outer space question

 P: 1,351 I get .........120/63.
P: 14
 Quote by denverdoc I get .........120/63.
oh really?

actually, its -1.9 m/s because the astronaut goes backwards.
Mentor
P: 8,272
 Quote by Mike667 oh really? actually, its -9.1 m/s because the astronaut goes backwards.
I think you may mean -1.9m/s
 P: 14 Haha, yeah ill change it.
P: 1,351
 Quote by Mike667 oh really? actually, its -9.1 m/s because the astronaut goes backwards.
Yes, and I actually chose the sign convention as such. Good lord trying to be helpful. And you'll notice, the question states the problems in terms of speed and asks for velocity. Either answer is correct.

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