Wavelength
The shortest repetition length for a periodic wave. For example, it is the distance from crest to crest or from trough to trough. In compressional waves, such as sound waves, it is the measurement of the distance from rarefaction to rarefaction, or compression to compression.
The wavelength of visible light lies in the range 400nm to 700nm.
The wavelength of audio waves in air lie in the range 0.017m to 17m (20Hz to 20kHz).
In all wave motion the shorter the wavelength, the greater the energy carried by the wave.
Wavelength, λ
where
c = wave speed [ms-1]
f = frequency [Hz]
k = wavenumber [m-1]
| Violet (visible light) | 4x10-7m |
| Red (visible light) | 7x10-7m |
| 20kHz audio waves | 0.017m |
| VHF radio waves | 1 to 10m |
| 20Hz audio waves | 17m |
| VLF radio waves | 10km to 100km |
See also: Angular Frequency, Frequency, Microwaves, Period, Phase, Waveband, Wavenumber.
Subjects: Noise & Vibration Physics