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Uh Hi help me please?

  1. Oct 9, 2008 #1
    1. The problem statement, all variables and given/known data
    A jet engine gets it thrust by taking in air, heating and compressing it, and then ejecting it at a high speed. IF a particular engine takes in 20 k/g of air per second at 100 m/s and ejects it at 500 m/s calculate the thrust of the engine.
    chriss #getmoney: thrust of the engine would be v right?

    2. Relevant equations

    i believe that the equation is Mv1 + Mv2 = V(Mv1+Mv2) and that the thrust = V .

    3. The attempt at a solution
  2. jcsd
  3. Oct 11, 2008 #2


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    Thrust is a force rather than velocity.

    Hint: Try using Newton's Second Law.

    Edit: The equation that you have written doesn't make sense, it simplifies to V=1 for all M and v.
    Last edited: Oct 11, 2008
  4. Oct 11, 2008 #3


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    Welcome to PF!

    Hi chrishere?! Welcome to PF! :smile:

    Thrust is a force, so use Newton's second law in the form force = rate of change of momentum.

    How much momentum is being ejected? :wink:
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