Science Buddies: "Ask an Expert"

I have a question regarding the Guitar Fundamentals project. Our results plus calculations yielded a speed of sound on the high E string of a guitar at 418.63m/s. When I look up the speed of sound, it is about 343m/s. Are our results inaccurate?

We measured the length of the string at 63.5cm.
We measured the frequency of the high E string when unfretted at 329.63.

We used the formula: speed of sound = (frequency)(2 times the length of the string)

Any help would be appreciated.

Hi ShmaInstitute,

I'm assuming that you're working on the project described here:

https://www.sciencebuddies.org/science- ... ed#summary

In this experiment you use the measured string length and frequency to calculate the speed of a standing wave along the string. Based on the information you posted you've used the correct equation to calculate the wave speed. This is not the same as the speed of sound, which is how fast a sound wave moves in a medium (like air). You'd need a different experiment to measure the speed of sound.

The references in the project bibliography include detailed information about the physics of vibrating strings and standing waves. In addition the following link should be useful to you:

http://hyperphysics.phy-astr.gsu.edu/hb ... ta.html#c1

I hope this helps. Please ask again if you have more questions.

A. Norman