Wave velocity is inversely proportional to the wavelength of the wave. This means that as the wavelength increases, the wave velocity decreases, and vice versa.

Here's why:

* Wave velocity (v) is the speed at which a wave travels through a medium.

* Wavelength (λ) is the distance between two consecutive crests or troughs of a wave.

* Frequency (f) is the number of waves passing a point per second.

The relationship between these three is given by the following equation:

v = fλ

From this equation, we can see that if the frequency remains constant, an increase in wavelength will lead to a decrease in velocity, and vice versa.

This relationship holds true for all types of waves, including electromagnetic waves (like light) and mechanical waves (like sound).