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Homework Help: How does radial forc vary with the radius of its circular path?

  1. Oct 16, 2009 #1
    1. The problem statement, all variables and given/known data

    Its a conceptual question:

    Theoretically, how does the radial force exerted on an object vary with the radius of its circular path when it is revolving: (a) at constant frequency? (b) with constant speed?

    2. Relevant equations

    F = mv^2/r

    3. The attempt at a solution

    Assuming that mass is constant, I had thought that the force would be inversely proportional to the radius of its circular path. I went to a physics tutor for help and now I am not sure of this lol - I am absolutely confused! :)

    What I am really confused at it is what is the difference between speed and frequency? I know that frequency is cycles per second, but how are they different in this equation (F = mv^2/r)?

    Thanks :)
  2. jcsd
  3. Oct 16, 2009 #2


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    F = m*v^2/r = m*ω^2*r = m*ω*v.
    ω=2π*f and v can speed.
  4. Oct 17, 2009 #3
    HI! :)

    Thanks for asnwering! :) But I am still confused :)

    I understand that Force is inversely proportional to Radius - but is it inversely proportional to radius when its at constant frequency? and constant speed?

    I understand that ω=2π*f is equation for frequency.

    hang on - does this mean that at constant frequency Force is directly proportional, but at constant speed force is inversely proportional??!! : )
  5. Oct 17, 2009 #4


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  6. Oct 17, 2009 #5
    Thanks!! :)
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