What term is used to describe the distance from the center of the peak or valley of a wave?

The term that refers to the distance from the center of the peak or valley of a wave is amplitude. Amplitude quantifies the height of the wave from its resting position, which can be observed as the distance from the equilibrium position to the crest (the peak) or trough (the valley) of the wave. This characteristic is crucial in understanding wave properties, as it determines the intensity or strength of the wave, whether in sound waves, light waves, or other types of waves.

The other terms have different meanings: frequency relates to how many cycles of the wave occur in a given time period, wave speed refers to the speed at which the wave travels through a medium, and wavelength is the distance between consecutive crests or troughs of a wave. Each of these properties plays a role in describing a wave, but amplitude specifically focuses on the vertical distance associated with the wave's extremes.