### Re: Is there an independent formula for the wavelength of sound in water?

Date: Wed Oct 25 11:37:34 2006
Posted By: James Holliday, Grad student, Physics Department, University of California, Davis
Area of science: Physics
ID: 1160020013.Ph
Message:

Melodie,

Greetings. As you know, sounds are bundles of energy that propagate through matter as (solids, liquids, and gases) waves. As such, different sounds can be characterized by the properties of their the sound waves. These properties are frequency, wavelength, period, amplitude, and velocity. In an ideal experiment, the velocity of a sound wave is equal to the product of its frequency and its wavelength:

velocity = frequency * wavelength

As I understand your question, you plan to send a sound through water and want to know how to determine its frequency and wavelength. You will then be able to calculate the experimental speed of sound and compare it with the theoretical speed of sound. This, unfortunately, is often hard to do in practice. Normal, everyday sounds are really a combination of lots of different "modes". Think of a mode as a pure tone. Each mode has its own frequency and wavelength, and by summing different modes together in different amounts, we can construct complex sounds.

For you to be able to calculate the speed of sound using frequency and wavelength, you'll need to be able to produce a pure mode or tone. This way you'll have an exact frequency and an exact wavelength. You can create pure tones using sound generators, tuning forks, or even musical instruments played one note at a time. Sound generators and tuning forks are nice in that the frequencies are often printed right on them.

Sincerely,

James R Holliday

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