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Homework Help: Final Velocity

  1. Oct 12, 2011 #1
    Final Velocity....

    Problem: A hockey puck is given an initial velocity of 40.0 m/s
    along the ice. Find the speed of the puck 1.00 s later if
    the coefficient of kinetic friction (U) between puck and ice is
    0.600. (HINT: The result is independent of the mass of
    the puck.)


    My solution:

    1. sum of forces in y direction = N - W = 0
    2. sum of forces in x direction = p - f = (a)

    p - (U)(N) = a
    p - (0.600)(g) = a
    p - 5.88 = a

    ( I need to know what "a" is in order to solve for final velocity but I am doing something wrong... please help)

    PS. is my body diagram correct?
     

    Attached Files:

  2. jcsd
  3. Oct 13, 2011 #2
    Re: Final Velocity....

    The initial push vector you have is basically zero. It has an initial velocity, but no force acting on it in that direction. You can set up F-ma with that as zero, and you should be able to solve it for acceleration.

    Take a look at this problem, it's very similar.
    https://www.physicsforums.com/showthread.php?t=539748
     
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