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Homework Help: Static friction vs kinetic friction (Very simple question)

  1. Mar 29, 2012 #1
    This isnt part of a homework question or anything, i was just curious

    If an object is at rest, static friction is at work, so for an object to move, on a flat surface, force applied must be greater than the static friction force yes?

    But this is not true for kinetic friction, where an object can move at a constant velocity, even though net force is 0, because force applied is the exact same as kinetic friction? Yes?

    thanks in advance :)
  2. jcsd
  3. Mar 29, 2012 #2


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    Staff Emeritus
    Science Advisor

    Yes. In order to get the object at rest to move, the applied force must exceed the static friction force.

    At constant velocity, there is no acceleration, and thus the net force = 0, and that means the applied force = the frictional force. If the net force > 0, there will be an acceleration, and if net force < 0, there will be a deceleration.
  4. Mar 29, 2012 #3
    ahhh ty!
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