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Homework Help: Kinetic friction of box down a ramp

  1. Feb 26, 2005 #1
    A box slides down a ramp inclined at 41 degrees horizonontal with an acceleration of 1.4 m/s^2. The acceleration of gravity is 9.8 m/s^2. Determine the coefficient of kinetic friction between the box and the ramp.

    no ideas need any advice
     
  2. jcsd
  3. Feb 27, 2005 #2

    xanthym

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    {Net Force On Box Parallel To Ramp} = {Gravity Parallel Component} - {Friction} =
    = m*g*sin(41 deg) - K*m*g*cos(41 deg)
    = m*g*{sin(41 deg) - K*cos(41 deg)}
    = m*a

    a = g*{sin(41 deg) - K*cos(41 deg)}
    (1.4) = (9.8){(0.6561) - K*(0.7547)}
    K = {(1.4/9.8) - 0.6561}/(-0.7547)
    K = (0.6801)


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