I'm not sure if this is the right place to ask this, but I'll try here... [I'm not physics student and don't know how to differentiate "intro physics" from "not intro physics"](adsbygoogle = window.adsbygoogle || []).push({});

I'm asked to calculate moment of inertia [around center of mass] for a thick disk.

The problem: I calculate the moment of inertia in two different ways and get different answers.

Way 1 [the crazy method] - I calculate moment of inertia for some inner part of the disk then I calculate the moment of inertia for the rest of the disk.

Way 2 [the standard method] - I calculate the moment of inertia of the whole disk continuously.

The mass of the outer disk is M/2 and so is the mass of the inner disk.

It is hard to to draw thing in the forums so I'm attaching my drawings and calculations as a picture: link.

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# Homework Help: Moment of Inertia calculation

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