weight of the pipe to the nearest pound

Question

The density of a PVC pipe is 1.38 grams per cubic centimeter. If the outer diameter is 4.5 inches and the PVC pipe has a thickness of 0.25 inches and a height of 10 feet, what is the weight of the pipe to the nearest pound?

Answer 1

outer diameter of pipe is 4.5 inches, so outer radius (RO) is 2.25 inches

inner diameter of pipe is 4 inches, so inner radius (RI) is 2 inches

volume = PI * (RO^2 - RI^2) * H

now can determine mass using formula

density = mass/volume

then determine weight using formula

weight = mass * gravity