The problem is to find a mass of cylindrical solid given its dimensions and the density of the solid. Density is defined as mass per volume of substance, therefore to find the mass, the volume of the solid must be known. Volume of cylinder = (PI) (r^2) h = (PI) (7^2) (8) = 1231.5043 cm^3 Using the density: Mass = (5 g/ 1 cm^3)( 1231.5043 cm^3) = 6157.5216 g