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Homework Help: Work:kinetic frictional force

  1. Oct 12, 2004 #1
    A 280 N force is pulling an 80.0 kg refrigerator across a horizontal surface. The force acts at an angle of 18.0° above the surface. The coefficient of kinetic friction is 0.200, and the refrigerator moves a distance of 6.00 m.
    (a) Find the work done by the pulling force.
    1.60*10^3 J
    (b) Find the work done by the kinetic frictional force.
    J

    I have the answer for part a, but i keep getting the wrong answer for part b. Can someone please help me solve this problem?
     
  2. jcsd
  3. Oct 12, 2004 #2
    for the work done by frictional force


    first of all Ff = coeff(Mu) times Normal force (N)

    so N + 280sin18 - 80g = 0

    Ff = Mu N

    Work done by friction is Ff times distance
     
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