# Resistance of a disk

Gyroscope

## Homework Statement

A disk with width b and radius a.
An element of resistance is:

$$dR=\rho \frac{2\pi r}{bdr}$$

How do I integrate this?

Thanks in advance.

## Answers and Replies

berkeman
Mentor
I don't understand your volume element. You are trying to get the total resistance between what two places? A point on one edge of the disk to a point on the other side, or from the center out to the perimiter, or what?

Gyroscope
It's the sum of the resistances of each ring of the disk.