The frequency of a wave is a measure of how many waves pass a given point in a certain amount of time. It is measured in hertz (Hz), which is equivalent to one wave per second. The frequency of a wave is related to the source of the wave by the following formula:

$$f = v / λ$$

where:

* f is the frequency in Hz

* v is the wave velocity in meters per second

* λ is the wavelength in meters

This formula tells us that the frequency of a wave is inversely proportional to the wavelength. This means that as the wavelength increases, the frequency decreases, and vice versa.

The source of a wave determines its frequency. For example, the frequency of a sound wave is determined by the vibrations of the sound source. The faster the vibrations, the higher the frequency. The frequency of a light wave is determined by the energy of the photons that make up the wave. The higher the energy of the photons, the higher the frequency.

The frequency of a wave is an important property that can be used to identify the source of the wave and to determine its properties.