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Homework Help: Kinetics of Translation

  1. Mar 4, 2007 #1
    1. The problem statement, all variables and given/known data
    A 200kg body is supported by wheels @ B to roll freely w/o friction & by a sled @ A with which uk = 0.5. Compute the value of P to cause an acceleration of 0.02g. (g=9.8m/s^2)

    NOTE: Image not drawn to scale.
    http://www.geocities.com/timothybridge/kinOftrans.JPG

    2. Relevant equations

    Efx=max

    Efy=0

    Emcg=0

    Fa=uNa

    3. The attempt at a solution

    P-Fa=200(0.02)(9.8)

    Na+Nb=1960

    Nb(1.5)-Na(1.5)+P(1.2)-Fa(1.8)=0

    Fa=0.5Na

    solving 4 equations simultaneously,

    P=491.78N
    Na=905N
    Nb=1055N

    My professor said the answer should be around P=2350N

    Can someone identify what's wrong with my solution?
     
    Last edited: Mar 4, 2007
  2. jcsd
  3. Mar 5, 2007 #2

    Pyrrhus

    User Avatar
    Homework Helper

    Recheck your third and first equation.
     
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