Wavelength (λ): the distance the wave travels during one cycle. What are the units?

Units of Wavelength (λ)

1. Understanding Wavelength: Wavelength (λ) is defined as the distance between two successive crests (or troughs) of a wave. It is a measure of how long a wave is, and it plays a crucial role in various physical phenomena, including sound and light.

2. Common Units: The units of wavelength can vary depending on the type of wave being measured:

   • Meters (m): The standard unit in the International System of Units (SI) for measuring wavelength, particularly for sound and electromagnetic waves.
   • Nanometers (nm): Often used in the context of light waves, especially in the visible spectrum and for ultraviolet or infrared wavelengths, where 1 nm = $10^{-9}$ meters.
   • Centimeters (cm): Sometimes used for waves in specific contexts, such as radio waves, where wavelengths can be of a manageable length.
   • Millimeters (mm): Also applicable for certain types of electromagnetic waves.

3. Examples of Applications:

   • Wavelengths of visible light range from about 400 nm (violet) to 700 nm (red).
   • Sound waves in air can have wavelengths from a few millimeters to several meters, depending on the frequency.

In summary, the most common unit for measuring wavelength is meters (m), but it is often expressed in nanometers (nm) when dealing with light or other electromagnetic waves.