Description

Diagram is a long hollow cylinder, like a metal pipe, with walls of a certain thickness. The length of the cylinder is labelled h. The radius of the inner cylinder is labelled rinner and a line segment is drawn from the centre of the circle at one end of the cylinder to the inside wall of the cylinder. The radius of the outer cylinder is labelled rtotal and a line segment is drawn from the centre of the circle at the other end of the cylinder to the outside wall of the cylinder.