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Homework Help: Properties of matter

  1. Mar 11, 2006 #1
    Please help me in solving this problem.
    # A steel ring of radius r and cross sectional area A is fitted on to a wooden disc of radius R(R>r). If the Young’s modulus be Y, then what is the force with which the steel ring expands?
    I just don’t have any idea on how to go about this problem.
  2. jcsd
  3. Mar 11, 2006 #2


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    Is that the exact wording of the question ?

    It is extremely ambiguous, and as such, is bordering on nonsensical.
  4. Mar 11, 2006 #3
    For a very small portion of the ring ([tex]dl=Rd \theta[/tex]) you have the static equilibrium condition:
    [tex]2 T sin(\frac{d \theta}{2})=N[/tex]
    where N is the force between the ring and the cylinder. Now you use
    [tex]sin (\frac{d \theta}{2}) ~= \frac{d \theta}{2}[/tex]
    and T from the Young law for the small element [tex]dl[/tex] (when it expands between [tex]dl_0=r d \theta[/tex] and [tex]dl=R d\theta[/tex]) and so on....
    Last edited: Mar 11, 2006
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