Wavelength

In physics wavelength is the distance between repeating units of a propagating wave of a given frequency. It is commonly designated by the Greek letter lambda (λ). Examples of wave-like phenomena are light, water waves, and sound waves. The wavelength is related to the frequency by the formula: wavelength = wave speed / frequency. Wavelength is therefore inversely proportional to frequency. Higher frequencies have shorter wavelengths. Lower frequencies have longer wavelengths, assuming the speed of the wave is the same. 在物理波長的距離是一個波傳播的一個給定頻率的重複單元之間的。它是由希臘字母λ通常指定（λ）。波現象的光，水波和聲波的例子。波的頻率相關公式：波長=波速/頻率。因此，波長與頻率成反比。高頻率的波長短。較低的頻率的波長較長，假設波的速度是相同的

Wavelength of a sine wave.

In a wave, properties vary with position. For example, in a sound wave the air pressure oscillates, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary.

Visible light ranges from deep red, roughly 700 nm, to violet, roughly 400 nm (430–750 THz). For other examples, see electromagnetic spectrum. The wavelengths of sound frequencies audible to the human ear (20 Hz–20 kHz) are between approximately 17 m and 17 mm, respectively. So the wavelengths in audible sound are much longer than those in visible light.

Speed=wavelengh×frequency

一個正弦波的波長。

在一個波，性質不同的位置。例如，在聲波的空氣壓力振盪，而在光和其他電磁輻射的電場強度和磁場的變化。

可見光的範圍從約700 nm，深紅色，紫色，約400海里（430–750 THz）。其他的例子，看看電磁頻譜。聲音的頻率，人耳可聽的波長（20赫茲–20千赫）約17米和17毫米之間，分別。所以在聲音的波長比可見光長。

速度=波長×頻率