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Homework Help: Conical pendulum

  1. Aug 28, 2007 #1
    i was solving thsi problem
    and attempted it in this manner
    consider a length [tex]dx[/tex] of the rod at a distance [tex]x[/tex] from the pivot now
    let [tex]\theta[/tex] be the required angle
    [tex]dx\cos\theta = dm g[/tex]
    [tex]dx\sin\theta = m\omega^{2}x\sin\theta[/tex]
    dividing we get [tex]\tan\theta = \frac {\omega^{2}x\sin\theta}{g}[/tex] which is obviously false
  2. jcsd
  3. Aug 28, 2007 #2


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    Try drawing a free body diagram, with the three forces of gravity, tension and centripetus.
  4. Aug 28, 2007 #3
    well what's wrong with my approach
  5. Aug 29, 2007 #4
    the [tex]dx[/tex] should be replaced by [tex]dT(x)[/tex] the differential tension.but obviously still the problem is unsolved
  6. Aug 29, 2007 #5


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    Homework Helper

    pardesi, I think the problem with this approach is that it assumes that the net force acting on any part of the rod acts radially along the rod. This is not necessarily true.
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