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Homework Help: Outer space question

  1. Apr 26, 2007 #1
    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.
  2. jcsd
  3. Apr 26, 2007 #2


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    Conservation of momentum. Here, the total momentum before was zero. so th etotal momentum after will be zero.
  4. Apr 26, 2007 #3
    Yes, thats what i was thinking. thanks again.
  5. Apr 27, 2007 #4
    Is the answer 1.9 m/s?
  6. Apr 27, 2007 #5
    I get .........120/63.
  7. Apr 27, 2007 #6
    oh really?:rolleyes:

    actually, its -1.9 m/s because the astronaut goes backwards.
    Last edited: Apr 27, 2007
  8. Apr 27, 2007 #7


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    I think you may mean -1.9m/s
  9. Apr 27, 2007 #8
    Haha, yeah ill change it.
  10. Apr 27, 2007 #9
    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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