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A quick question about friction and applied force

  1. Nov 18, 2007 #1
    if the friction force is larger than the applied force. the object wouldnt move and the acceleration would be 0 right?
  2. jcsd
  3. Nov 18, 2007 #2
    If the friction force is larger than the applied force, The net force would move with the force of friction. in essence the Force of friction would become the applied force, the applied force would slow it down (apply friction)

    Newtons First Law: if [tex] a = 0; F_{applied} = F_{friction} [/tex] meaning any time acceleration is zero, the forces are balenced and equal eachother, if Ff is greater than Fp, e.g. Ff = 60 N, Fp = 50 N

    Fnet would be -10N as Fnet = Fp - FF

    Fnet = 50N - 60N
    Fnet = -10N so it would move and accelerate backwards.
  4. Nov 18, 2007 #3


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    No. If the applied force to an object is less than the static friction, the object does not move. The applied force will be balanced by an equal and opposite static force.
  5. Nov 18, 2007 #4
    so that means acceleration=0 and not a negative number right?
  6. Nov 18, 2007 #5


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    The force is static, hence no motion (i.e. no change in velocity), hence no acceleration.

    This assumes an object at rest.

    If one can get an object moving, and then the applied force equals the friction force, one can have a constant velocity, but no acceleration.
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