# Moment of Inertia - Hollow Objects

## Homework Statement

1. Given that the moment of inertia of a thin conical shell, of base radius a and height 3a, about
an axis through its apex perpendicular to its symemtry axis is 19
4 ma2, and that the centre of
mass of the shell is along its symmetry axis a distance a from the base and 2a from the apex,
find the moment of inertial of the conical shell about an axis which passes through its centre
of mass and is perpendicular to its symmetry axis.
2. A partially hollowed out thick uniform spherical shell, of mass m and outer radius a, has
moment of inertia 23
15 ma2 about a tangent. What is the moment of inertia of the shell about a
diameter, given that its centre of mass is at the centre of the shell?

## Homework Equations

I = Sigma m (r^2)

## The Attempt at a Solution

Lots on paper

Thanks tons, again this is for an exam tomorrow

tiny-tim
Homework Helper
Welcome to PF!

Hi JerS! Welcome to PF! (try using the X2 tag just above the Reply box )

Hint: use the parallel axis theorem …

what do you get? 