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Homework Help: Static Motion

  1. Oct 8, 2007 #1
    1. The problem statement, all variables and given/known data

    A stubborn 120 kg mule sits down and refuses to move. To drag the mule to the barn, the exasperated farmer ties a rope around the mule and pulls with his maximum force of 800 N. The coefficients of friction between the mule and the ground are mu,s = 0.8 and mu,k = 0.5. Is the farmer able to move the mule?

    The attempt at a solution

    friction=μs(normal force)
    friction=0.8(120kg)
    friction=120(9.8)(.8)
    frictionS=940.8
    940.8N>800N

    The farmer will not be able to get the mule to move.


    Does this look correct?
     
  2. jcsd
  3. Oct 8, 2007 #2

    G01

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    Looks good to me. By the way, is this problem from Knight's book? I know I remember it from somewhere...
     
  4. Oct 8, 2007 #3
    Haha, quite the memory. Yep, taken right from the book.
     
  5. Oct 8, 2007 #4

    G01

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    I tutor intro physics and they use that book at my university, so I must have done it recently at a tutoring session. So, my memory isn't that great.:rolleyes:
     
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