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Homework Help: Frictionless pulley and static equilibrium

  1. Jul 10, 2007 #1
    1. The problem statement, all variables and given/known data
    Two masses are connected by a string passing over a frictionless pulley. show that for this system to remain in static equilibrium where m1 sin O (theta) > m2 that (static friction coefficient) > or = tan O - m2 / m1 sec O.

    2. Relevant equations
    static friction coefficient > or = static friction / normal force

    3. The attempt at a solution

    I first tried reevaluating the trig components...changed tan into sin / cos and sec into 1 / cos. I figured that 1 / cos could be chaned to m2 / m1 x cos O. However, try as I might, I couldn't get from m1 sin O to the ending equation. I tried drawing free body diagrams for the pulley, I tried writing force statements for Fy and Fx...and I'm still lost. Please help!
  2. jcsd
  3. Jul 10, 2007 #2


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    Staff Emeritus
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    Gold Member

    What is theta?
  4. Jul 11, 2007 #3
    Theta was not given.
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