(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I'm having a bit of difficulty with this question on SHM:

"An automobile wheel and tyre are suspended in the horizontal plane by a vertical steel rod 5mm in diameter and 2m long, which is bolted to the wheel axis. The wheel is given a small angular deflection, and makes 10 oscillations in 30.2s. Calculate the polar moment of intertia of the wheel and rod. Assume G = 80 GNm^{-2}.

2. Relevant equations

I've got the following equations but I don't think I've got the right variables to be able to use them. Is there something I'm missing?

[tex]\theta=[/tex][tex]\frac{TL}{JG}[/tex]

Where [tex]\theta[/tex] = torsional deformation, T = torque, L = length, J = polar moment of inertia, G = shear modulus

Also

k = [tex]\frac{T}{\theta}[/tex]

I'm not sure where the number of oscillations comes into it, although I know period = 0.302s

Any help much appreciated, thanks

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# Polar Moment of Inertia

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