# Question Video: Relating the Frequency of a Sound Wave to Its Wavelength

What frequency sound has a 0.10-m wavelength when the speed of sound is 340 m/s?

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### Video Transcript

What frequency sound has a 0.10-meter wavelength when the speed of sound is 340 meters per second?

Letβs call the value of 0.10 meters, the wavelength, π. And weβll call the speed of sound, 340 meters per second, π£ sub π . We want to solve for the frequency associated with these two values; weβll call that frequency π.

In this example, the relationship that helps us connect these three terms has to do with wave speed. And since sound is a wave, it obeys this equation which says that wave speed π£ is equal to wave frequency π times wavelength π. When we apply this relationship to our scenario, itβs the speed of sound, π£ sub π , that is equal to wave frequency, π, we want to solve for times wavelength, π.

If we rearrange this equation to solve for π, we see that it equals the speed of sound π£ sub π  divided by π. Plugging in for those two values, when we calculate this fraction, we find that the frequency π is equal to 3.40 thousand hertz or kilohertz. Thatβs the frequency associated with this wavelength and wave speed.