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Homework Help: One More Accelerated Parallel Force

  1. Nov 22, 2006 #1
    "For a 5.0 kg object on a horizontal surface that has a coefiicient of static friciton where us = 0.15 and a coefficient of kinetic friction where uk = 0.07, what is the parallel force necessary to accelerate the object at 12 m/s^2."

    a) 53.6 N
    b) 56.6 N
    c) 60.0 N
    d) 63.4 N
    e) 67.4 N

    I found that the normal force (FN) is 49 N. The max force is 7.35 N. However, I dont know how I would go about finding a force needed to accelerate an object. .....help.....
     
  2. jcsd
  3. Nov 22, 2006 #2

    berkeman

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    Staff: Mentor

    Which mu should you use if the object is moving? The force in F=ma will be the combination of the frictional force and the force required to accelerate the mass....
     
  4. Nov 22, 2006 #3
    by using F=ma, 5*12, I get 60. For the uk force, I multiplied 49*.07. then uk force + force = 63.4, answer D
     
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