# Volume of copper Question [closed]

A copper pipe, used for plumbing from the water main to a house, is $3$ meters long and has a circular cross-section $2.8 cm$ in diameter. There is a $2 cm$ diameter hole in the center of the cross-section for the entire length of the rod. What is the volume of copper in the rod in cubic inches? The density of copper is $559 \large \frac{lbm}{(ft)^{3}}$. What is the mass of the copper pipe in pounds?

-

## closed as off-topic by 900 sit-ups a day, Daniel Rust, Jonas Meyer, Hakim, glaceJul 4 at 0:31

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – 900 sit-ups a day, Daniel Rust, Jonas Meyer, Hakim, glace
If this question can be reworded to fit the rules in the help center, please edit the question.

Hint: The volume of a cylinder of radius $r$ and height $h$ is $\pi r^2 h$. You have one cylinder with a cylindrical hole in it, so subtract the volume of the hole from the outer cylinder. Then for the mass, you need to watch the units.