Wave frequency

The frequency of a wave is the number of complete waves that pass a given point in one second.

Notation

We usually use the letter f to represent frequency. Nice and simple :)

Units

Frequency is measured in hertz (Hz).

One hertz is equal to one wave passing a point per second.

Calculating frequency

Frequency can be calculated using the re-arranged formula for wavelength and wave speed:

\text{Frequency} = \frac{\text{speed of wave}}{\text{wavelength}}

Or, using symbols:

f = \frac{v}{\lambda}

Where:

• f is the frequency (in hertz, Hz)
• v is the speed of the wave (in metres per second, m/s)
• \lambda is the wavelength of the wave (in metres, m)

Relationship with wavelength

It is inversely proportional to the wavelength of the wave - that is, as frequency increases, wavelength decreases, and vice versa.

This assumes that the speed of the wave remains constant.