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Homework Help: Tow truck dragging Tractor

  1. Mar 25, 2007 #1
    1. The problem statement, all variables and given/known data
    The coefficient of limiting static friction of a rubber tire in wet concrete is 0.70. What mass of tractor, with its brakes locked, can be dragged by a tow truck that can exert a horizontal force of 1.0 * 10^4 N?

    2. Relevant equations
    Fnetx = ma

    Ff = us*Fn

    Fn = m*g

    3. The attempt at a solution
    10000 / (0.70*9.8) = 1457.72

    Is that right??..........Help NEEDED:confused:
  2. jcsd
  3. Mar 25, 2007 #2
    What you calculated is the maximum mass of a tractor that can be moved, starting from rest on a horizontal surface, by a tow truck. Because the coeff. of kinetic friction is less than that of static friction, a more massive tractor could be pulled if it started with a nonzero speed. NOTE: I am just nitpicking the question, your solution seems fine to me.
  4. Mar 25, 2007 #3
    oo so thaz rite??
  5. Mar 25, 2007 #4
    yes, good.
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