Extra Credit: Measure the speed of sound

Measure the speed of sound in air.

This project may be done by teams of 2-3 individuals. The goal is to measure the speed of sound in air.

You must design an experiment which allows you to measure the speed of sound waves in air. One straightforward method is to measure the time it takes a sound wave to travel some distance. The larger the distance, the better. You can look up the speed of sound in your textbook or the notes to get an estimate for the size of the area in which you'll carry out the experiment.

There are other methods to measure the sound speed, too. You may adopt any method you wish, as long as you describe clearly how your method works.

If necessary, you can borrow a stopwatch from the stockroom. You _might_ use a meterstick to measure distances, but perhaps you can think of some way to use a distance which has already been measured accurately.

Make sure you measure the temperature of the air during your experiment. In order to compensate for the effects of wind (which will speed up sound waves going downwind, and slow those going upwind), make two sets of measurements, in two opposite directions, and then average the results.

Once you've made the measurements and calculated the speed of sound, compare it to the speed you would have expected. How close are the two values? If there is a large difference (more than 10 percent), try to explain it.

Submit a report which contains a description of your method, with a clear drawing and all relevant dimensions. Include the data (air temperature and all raw time measurements) for your experiment, and all calculations. You may also include interesting items you discovered during the course of the procedure.

This page maintained by Michael Richmond. Last modified Apr 8, 1998.