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Homework Help: Friction & Impending motion

  1. Dec 13, 2012 #1
    1. The problem statement, all variables and given/known data

    I'm trying to understand the whole impending motion stuff.

    2. Relevant equations

    Eq.1: F = μsN
    Eq.2: F ≤ μsN

    3. The attempt at a solution

    After obtaining my normal forces and friction force from analyzing my FBD, I should set up the data using these two equations?

    And so.....if Eq.1 is satisfied then the object, lets say a box, will start to move? And if Eq.2 is satisfied the box will not move?
  2. jcsd
  3. Dec 13, 2012 #2

    rude man

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    Gold Member

    In a wod - correct.

    Once eq. 1 is met, the box slides and there is a new coeff. of friction involed, μd or 'dynamic' friction. This coefficient is the ratio of the force F needed to keep the box moving without acceleration to the weight N of the box. μd is generally < μs as I recall (been a long, long time ....).
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