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Major Help Required

  1. May 19, 2006 #1
    Question on Kinetic and potentail energy!

    I need some major help on the physics question below. I need help quit quickly. I'm sorry if this thread is in the wrong section, but i don't think i have ever seen anything like this before. This is the question:

    The Speed of the rocket shown, of mass 20 000kg, has to be increased by 5.0 m/s Squared. If it burns 10kg of fuel and oxygen in doing this, what is the speed of the exhaust gases produced?

    The diagram of the rocket is irrelivent

    I need someone to please explain how to work it out? I just can't figure it out.

    Last edited: May 19, 2006
  2. jcsd
  3. May 19, 2006 #2


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    Homework Helper

    "has to be increased by 5.0 m/s Squared"

    What does this mean?
  4. May 19, 2006 #3


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    Staff: Mentor

    Yeah, speed can't be increased by 5m/s^2. Maybe 5m/s? Or is the acceleration 5m/s^s for some amount of time delta-t?
  5. May 19, 2006 #4
    If it's 5 m/s, it's just conservation of momentum:

    20,000 kg * (5 m/s) = 10 kg * v

    So v = 20,000 / 10 * 5 m/s = 10,000 m/s.
  6. May 20, 2006 #5
    From the given above, I agree that we need to use the equation in conservation of momentum.
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