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Homework Help: Finding final Velocity given mass, force, and displacement

  1. Mar 3, 2010 #1
    1. The problem statement, all variables and given/known data

    2.78 kg block is pulled (from rest) by a force (horizontal surface) of 15.8 N. The coefficient of kinetic friction is .106. What is the velocity after 2.88 m?

    2. Relevant equations
    fk=N(uk)
    Vf=sqrt((2*W)/m



    3. The attempt at a solution

    I attempted to find the final velocity by first finding the work (w=Fx*deltax) and then plugging it into the Vf equation I have listed.
     
  2. jcsd
  3. Mar 3, 2010 #2

    tiny-tim

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    Hi Bearbull24.5! :smile:

    (have a mu: µ and a square-root: √ and a delta: ∆ :wink:)
    That should be ok (assuming that m is inside the bracket). :confused:

    What figures did you get?
     
  4. Mar 3, 2010 #3
    I got 5.7 for the final velocity and a work of 45.504 N m
     
  5. Mar 3, 2010 #4
    Do I need to use the coefficient of kinetic friction for anything?
     
  6. Mar 3, 2010 #5

    tiny-tim

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    No, you need to use the net force. :wink:
     
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