How Fast Is Sound?

An experiment

- By Rachel Bithell

Sound is fast, but not too fast for you to measure its speed. You and a friend can find out how fast sound travels through air with just a few things you probably have at your house and some math you already know. Don’t worry—a calculator will do the hard part for you. The only thing that could be a little tricky is finding a good location. You’ll need an open area outside a large building with a mostly flat wall. A field next to a school or a parking lot next to an office or hospital usually fits the bill. Ask an adult to OK your experiment location.

You’ll need

A long tape measure (in feet or meters)

Tape, chalk, or stick to mark the ground

Stopwatch or a stopwatch app on a smartphone

Thermometer or a weather app on a smartphone

Calculator or a calculator app on a smartphone

Pencil and paper

A friend or other partner