along the direction of wave propagation, the distance between two adjacent in-phase particles is called the "wavelength". it refers to the distance between any two particles with a phase difference of 2π in a fluctuating medium. for example, in longitudinal waves, the distance between the centers of two adjacent sparse parts or the distance between the centers of two adjacent dense parts is also equal to the wavelength. in a transverse wave, the distance between two wave troughs or the distance between two wave crests is also equal to the wavelength. it can be seen from the definitions of wave speed and wavelength: in one period of particle vibration, the distance the vibration state propagates is exactly one wavelength, so λ=v/f, or λ=vt. it can be seen from the above formula that waves of the same frequency, the speed of waves in different media is different, so the wavelengths are also different. in the formula, λ represents the wavelength. wavelength, wave speed and wave source vibration frequency are called the three elements of waves.

sound wavelength: w = v/f

here

w = wavelength

f = wave frequency

v = wave speed