The outer ring of the wheel has a mass of 60 kg, the inner ring, 6 kg, and each spoke, 12 kg. Find the mass moment of inertia of the wheel about an axis through A and perpendicular to the page. Assume r1 =116 cm, r2 =39 cm.

Question

anonymous · Answer

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anonymous · Answer

u can individually calculate the M.I of the rings and the spokes and then add them all together. 
Rings are easy ya? . what about the spokes.. any idea as to how u would do that?

rajat97 · Answer

this is a good question 
and @Mashy  is right
you should calculate the moment of inertia of the two rings (mr^2)
next , you should use the parallel axis theorem to find the moment of inertia of the spokes and multiply it by the no. of spokes and add the moment of inertia of the two rings to this result
(Ix=Ic.m. + md^2 
where icm is the moment of inertia of the rod about its centre of mass and d is the distance of the centre of mass from the ref. point.)
and i got the answer 120.6686