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Circular motion problem

  1. Sep 28, 2008 #1


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    1. The problem statement, all variables and given/known data
    An inextensible spring with a longitud [tex]L[/tex] has a body attached on one of its side (at point [tex]Z[/tex] in my figure). The other side of the spring remains fixed (at the center of the circular motion).
    The body experiment the gravitational force since the circle is in a vertical plane.
    Calculate the minimal velocity (or speed?) when at point [tex]A[/tex] that must have the body in order to not be deviated from its circular motion.

    2. Relevant equations

    3. The attempt at a solution I've thought a lot about the problem, but I'm really lost. I know the formulas to encounter the velocity and all this but I don't know how to apply them in this example. I know that if the velocity at point A is 0 then the body will fall vertically. If the velocity is very little then the body will describe a parabola and be deviated from its circular motion... And if he has the velocity I must find, it will remains on its circular motion. I find the problem very interesting but I'm at a loss! I need to be started, like "what happens when the body is at point [tex]A[/tex] and its velocity is the one you are looking for?", because I just don't know.

    Attached Files:

  2. jcsd
  3. Sep 29, 2008 #2
    Thats easy just take into account centrifugal acceleration.
  4. Sep 29, 2008 #3


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    I got lucky today, I could ask a professor about
    , he told me that the tension must equals [tex]0[/tex].
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