# Calculating an object's moment of inertia

1. Nov 21, 2004

### Geoffrey F. Miller

What equation(s) is/are used to calculate an object's moment of inertia?

2. Nov 21, 2004

### cepheid

Staff Emeritus
I think it's given by the volume integral:

$$I = \iiint_V{\rho(\vec{r})r^2}dV$$

where

$\rho(\vec{r})$ is the density,

$r$ is the distance from the axis about which the moment of inertia is being calculated.

I'm not totally sure on that though...