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Homework Help: Rocket Momentum

  1. Oct 10, 2007 #1
    1. The problem statement, all variables and given/known data
    Far in space, where gravity is negligible, a 495 kg rocket traveling at 85.0 m/s fires its engines. The impulse imparted to the rocket is 15000Ns, for 30 seconds. What is the maximum velocity of the rocket?

    2. Relevant equations
    F(delta t)=mv2-mv1

    3. The attempt at a solution
    Why isn't this answer correct?
  2. jcsd
  3. Oct 10, 2007 #2


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    The impulse is given as 15000 Newton-seconds. you have incorrectly used this value as a force of 15000 newtons.
  4. Oct 10, 2007 #3

    D H

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    Staff Emeritus
    Science Advisor

    Force has units of Newtons, not Newton-seconds. The impulse, 15000Ns, is not a force. The time duration has already been factored in.
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