Properties of matter

[Amith2006]

Sir,
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.

[Gokul43201]

Is that the exact wording of the question ?

It is extremely ambiguous, and as such, is bordering on nonsensical.

[clive]

For a very small portion of the ring (dl=Rd \theta) you have the static equilibrium condition:
2 T sin(\frac{d \theta}{2})=N
where N is the force between the ring and the cylinder. Now you use
sin (\frac{d \theta}{2}) ~= \frac{d \theta}{2}
and T from the Young law for the small element dl (when it expands between dl_0=r d \theta and dl=R d\theta) and so on....