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Homework Help: Weight pulled on Incline

  1. Oct 20, 2008 #1
    1. The problem statement, all variables and given/known data

    A weight, mass m = 80 kg , is pulled over a rough horizontal plane, mu = 0.15, by a force of magnitude F = 359 N, making an angle of 43 degrees with the plane, away from the plane. Calculate the speed of the weight d= 1.5 m away from its initial position assuming that it started from rest.

    2. Relevant equations

    Ff = muFn

    Vf2 = Vi2 + 2ad


    3. The attempt at a solution

    The applied force is evaluated in the x direction only (since the object remained on the floor)

    therefore : Fappx = 359 cos 43 = 262.56N

    Fn = mg , therefore
    Ff = 0.15(80)(9.8) = 117.6N
    sumFx = 262.56 - 117.6 = 144.96N

    which means:::: ma = 144.96N
    80a = 144.96
    a = 1.812

    given Vf2 = Vi2 + 2ad, and vi = 0 (rest)

    then Vf2 = 2 (1.812)(1.5)

    Vf = 2.33 m/s


    -------> This is what Ive done on the question, im having doubts though, can anyone please verify / correct anywhere Im wrong? Please and Thank you
     
  2. jcsd
  3. Oct 21, 2008 #2
    It seems right to me. Why do you have doubts?
     
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