#### rock.freak667

Homework Helper

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**1. Homework Statement**

Say I am given some curve f(x,y) (revolved around some axis), how do I find the moment of inertia about an axis?

I know how to find the moment of inertia of things like a uniform rod, ring and sphere using

[tex]I=\int r^2 dm[/tex]

I believe I am supposed to to pick an elemental piece such that the revolved element is through the axis I want. But if I use I=[itex]\int[/itex]r

^{2}dm, I don't get anywhere.

I've various places that I am to use a double integral or even a triple integral. But I don't know how to set these up to compute the moment of inertia.