2.1.2 Characteristics of Waves: Wavelength

Look a little closer at the peaks and the troughs. The distance between two adjacent (next to each other) peaks is the same no matter which two adjacent peaks you choose. So there is a fixed distance between the peaks.

Looking closer you'll notice that the distance between two adjacent troughs is the same no matter which two troughs you look at. But, more importantly, it is the same as the distance between the peaks. This distance, which is a characteristic of the wave, is called the wavelength.

Waves have a characteristic wavelength. The symbol for the wavelength is . The units are meters (m).

The wavelength is the distance between any two adjacent points which are in phase. Two points in phase are separated by an integer (0, 1, 2, 3,...) number of complete wave cycles. They don't have to be peaks or troughs but they must be separated by a complete number of waves.