- #1

Peach

- 80

- 0

## Homework Statement

A sphere consists of a solid wooden ball of uniform density 800kg/m^3 and radius 0.20 m and is covered with a thin coating of lead foil with area density 20kg/m^2

Calculate the moment of inertia of this sphere about an axis passing through its center.

## Homework Equations

I_cm = m(r^2)

## The Attempt at a Solution

1. I took the volume formula of the sphere which is 4/3*pi*r^3 to get the volume and then multiply by its density to get the mass of the solid ball inside the sphere.

2. Then I did the same with the lead coating, only using the surface area formula A = 4*pi*r^2

(This I'm not sure about because I don't understand the picture. Is the solid ball centered in the sphere? Because I took the radius to be .20m assuming that it is and that it takes on the shape of the sphere...)

3. I combined the mass to get total mass and then multiply with the radius (.20m) with respect to the x and y axis.

But yeah, it's wrong. Someone pls guide me...somehow. :uhh: