- #1

Yuriick

- 5

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## Homework Statement

I was given a sample of 5000 points from an ellipsoidal blob (in 3D) that has some orientation. Assuming that each point has equal mass, I was asked to calculate the inertia tensor of this blob, then ﬁnd the principal axes to determine the orientation of this blob.

## Homework Equations

R = [itex]\frac{1}{M} [/itex][itex]\sum m_{i}r_{i}[/itex]

where M is the sum of the masses of every point

R is the center of mass

I = - [itex]\sum m_{i} [r_{i} - R][r_{i} - R][/itex]

## The Attempt at a Solution

Since all the mass for every particle is the same, the formula for center of mass becomes,

R = [itex]\frac{1}{5000} [/itex][itex]\sum r_{i}[/itex]

however I'm not sure how to find the inertial tensor since I don't know the mass of each particle.

Any help would be much appreciated, thanks!