Calculate the wavelengths in air at 20 degrees celsius for sounds at 20 hz and 20000 hz

Speed of sound in air at 20 degrees C is approximately 343.2 m/s.

For 20Hz, it means the wave cycle repeats itself 20 times in one second while traveling 343.2 m. 343.2 meters divided into 20 segments (one per cycle) comes out to 17.16m. Likewise: 343.2 / 20,000 = 17.16mm.

I Hope that made sense...

If you know that formula, you can apply it:



v is the speed of sound, which is 343.2 m/s as InfoJunkie pointed out.
f is the frequency of that wave (a sound is a wave)
lambda is the wavelength.

Since you have v and f, you can find lambda, and this turns out like what InfoJunkie said.

I suppose I should have shown the equation first. I tend to look at things visually and then understand them from there. I find I best understand it if I can find where the math came from.

Sure, that's why I put 'if you know the formula' :)

Most of the time, we understand things better when 'viewed', but making drawings and attaching them is quite a job!