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Homework Help: Work of a pitcher on the ball

  1. Nov 1, 2006 #1
    A baseball leaves a pitcher's hand at a speed of 41.0 m/s. The mass of the baseball is 0.142 kg . Ignore air resistance. How much work has the pitcher done on the ball in throwing it?

    I've tried using (1/2)mv^2, but there has got to be something weird going on, or i could just be using the wrong equation


    thanks for any and all help :smile:
     
  2. jcsd
  3. Nov 1, 2006 #2
    work

    i work it out and get the same thing every time i have tried it.
    2.911 Joules is the answer I get, and WebAssign says that it is incorrect.
     
  4. Nov 1, 2006 #3

    Doc Al

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    Staff: Mentor

    How are you getting that answer? Show what you did.
     
  5. Nov 1, 2006 #4
    sorry

    Sorry about not showing all the work.

    I just take the givens: v=41.0 m/s m=0.142 kg

    Then I plug it in to: [tex] \frac{m*v^2}{2} [/tex]

    [tex] \frac{41*0.142}{2} [/tex]



    That is the answer i come up with (2.911 Joules)
     
  6. Nov 1, 2006 #5

    rsk

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    square your 41, boy!
     
  7. Nov 1, 2006 #6
    duh. thanks i knew i was doing something completely dumb.
    always gotta forget the easy part.

    right answer = 119.351 Joules

    thanks a lot
     
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