# Homework Help: Students were testing their hearing range

1. Apr 12, 2010

### Brittykitty

In an experiment, students were testing their hearing range and found that it averaged about 25 Hz to 18 000 Hz. What are the wavelengths of sound waves producing these frequencies in air where the speed of sound is 343 m/s?

Would I use the formula

wavelength= velocity/ frequency?

wavelength = 343ms/25hz

and

wavelength = 343ms/18000hz ??

2. Apr 12, 2010

### Staff: Mentor

Re: Frequencies

You're basically using the right formation, but be careful to carry your units along correctly. You've written ms a couple of time where you mean m/s.

It's helpful to put units in square brackets (at least for me), and do math on the units at the same time you do math on the numbers. Cancel anyplace you get the same unit on the top and bottom of a division. So your equation could look more clear like this:

wavelength [m] = 343 [m/s] / 18000 [Hz] = 343 [m/s] / 18000 [1/s], etc...

3. Apr 12, 2010

### Brittykitty

Re: Frequencies

Thank you =) so...

wavelength [m] =343[m/s] / 18000 [Hz] =0.019m

and wavelength [m] =343[m/s] / 25 [Hz] =13.72m

does that look right to you?

4. Apr 13, 2010

### Staff: Mentor

Re: Frequencies

I didn't check the calculations, but the approach seems correct. Good work.