Ira Dorfman, Executive Director and Coordinator of the Greater Washington Region Clean Cities Coalition, is an internationally recognized expert in energy policy, alternative fuels, environmental transportation policy and international project development.
Wavelength is also measured in metres (m) - it is a length after all. The frequency, f, of a wave is the number of waves passing a point in a certain time. We normally use a time of one second, so this gives frequency the unit hertz (Hz), since one hertz is equal to one wave per second. Don't get confused with this quantity frequency. It is not a distance travelled by waves, nor is it a speed, although it is linked to both of these quantities.
A sound wave's frequency is a number that tells you how many waves pass by each second. Frequency is measured in Hertz (Hz). So for example, 60 Hz, the frequency of most TVs, is 60 waves per second. Or in the case of television, this means that the picture refreshes 60 times a second.