- #1

yang09

- 76

- 0

## Homework Statement

Determine the moment of inertia of a cylinder

of radius 0.37 m, height 1.8 m and density

(1.11 − 0.555 r + 0.284 r2) kg/m3 about the

center.

Answer in units of kg · m2.

## Homework Equations

I=Integral[(r^2)dm]

I = mr^2

Density = Mass/Volume

Volume of a cylinder = (Pie)(radius^2)(Height)

## The Attempt at a Solution

I used the density formula and solved for mass, Mass = (Density)(Volume). To get the volume, I used the volume for a cylinder formula and plugged in my numbers. From the volume and density, I got mass = (1.11-0.555r+0.284r^2)(Pie)(.37^2)(1.8). I then plugged my mass into the Inertia equation, getting I = (mass)(.37^2). I calculated it all out and got I = 0.099997.

This is wrong and I don't know what I'm doing wrong. Am i supposed to integrate the radius, but that wont do anything because r is a constant.