When you listen to music on the radio, the music is travelling to you through radio waves. In choosing your radio channel, you select the **
frequency.**

The radio above is set on 107.3. That means that the radio will be receiving radio waves at the frequency of 107.3 megahertz (MHz). That’s 107,300,000 hertz (one hundred seven million, three hundred thousand waves per second). Can we find the wavelength of the energy bringing us the music?

Wavelength and frequency are related by an equation:

*Speed of the wave* = *Frequency* x *Wavelength*

We can use the equation to find the *Wavelength of our radio station*. We just rearrange it so that the *wavelength* is on the left.

*Wavelength* = *Speed of the wave* / *Frequency*

The *speed of the wave* is always the same. It is the velocity of light in a vacuum, 3.00x108 meters/second. So now we can find the size of the wavelength.

We can write this equation using symbols instead of words:

**C** = speed of light

**λ** = wavelength

**f** = frequency

So the equation is **C=λf**