Mathematics

Problem

A circular lamina of radius

3\text{ m}

lies in the plane and has surface density

\sigma(r)=2r

kilograms per square meter, where

r

is the distance from the center in meters. Determine the total mass of the lamina. a)

27\pi\text{ kg}

36\pi\text{ kg}

18\pi\text{ kg}

54\pi\text{ kg}