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Homework Help: Work-Energy Theorem

  1. Sep 8, 2005 #1
    I'm having trouble with where to begin with this question, if anyone has guidance I'd be grateful.

    A space ship of mass 5.00 x 10^4 kg is travelling at a speed 1.15 x 10^4m/s in outer space. Except for the force generated by its own engine, no other force acts on the ship. As the engine exerts a constant force of 4.00 x 10^5 N, the ship moves a distance of 2.50 x 10^6 m in the direction of the force of the engine.
    a) Determine the final speed of the ship using the work-energy Theorem.
     
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  3. Sep 8, 2005 #2

    quasar987

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    The work is just a name people gave to "change in kinetic energy". If you find the work "done by the engine" in the ship going a distance of 2.50 x 10^6 m, then you've found the change in kinectic energy of the ship. And work in one dimension is simply

    [tex]W =Fd[/itex]

    where d is the distance traveled and F the force applied during this travel.
     
  4. Sep 8, 2005 #3
    Thanks, so If I solve for W, I get 1.00 x 10^12, then I make this answer equal to 1/2mv^2 - 1/2mv(o)^2, and plug in everything I have and solve for v, this should give me the correct answer?
     
  5. Sep 8, 2005 #4

    quasar987

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    Correct-o-mundo!

    Edit: except for the answer to W!
     
    Last edited: Sep 8, 2005
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