What characteristic of a wave determines its frequency?

The characteristic of a wave that determines its frequency is the distance between successive crests, also known as the wavelength. Frequency is defined as the number of oscillations or cycles that occur in a given time period, typically measured in hertz (Hz). The relationship between wavelength and frequency is described by the wave equation, which states that the speed of a wave is the product of its frequency and its wavelength.

When the speed of the wave is constant, a shorter wavelength means that the waves are closer together, resulting in a higher frequency. Conversely, a longer wavelength indicates that the waves are spaced further apart, leading to a lower frequency. Therefore, changes in the distance between crests directly affect the frequency of the wave.

The amplitude of the wave refers to the maximum displacement from the rest position and does not influence the frequency. The speed of the wave is relevant but is not the characteristic that directly determines frequency; it is the relationship between speed, frequency, and wavelength that is key. The energy of the wave is related to its amplitude and frequency, but it does not directly determine frequency itself. Thus, the distance between successive crests is the defining factor for determining the frequency of a wave.