Frequency

Frequency is how often an event repeats itself over a set amount of time.^[1]

In physics, the frequency of a wave is the number of wave crests that pass a point in one second (a wave crest is the peak of the wave).

Hertz (symbol Hz) is the unit of frequency.

The relationship between frequency and wavelength is expressed by the formula:

${\displaystyle f=v/\lambda }$

where v is speed and ${\displaystyle \lambda }$ (lambda) is wavelength. The formula for the frequency of light waves is ${\displaystyle f=c/\lambda }$ where the c is the speed of light.^[2]

All electromagnetic waves travel at the speed of light in a vacuum but they travel at slower speeds when they travel through a medium that is not a vacuum. Other waves, such as sound waves, travel at much much lower speeds and can not travel through a vacuum.

Examples of electromagnetic waves are: light waves, radio waves, infrared radiation, microwaves, and gamma waves.

1. ↑ "Definition of FREQUENCY". Retrieved 3 October 2016.
2. ↑ ""Frequency of a wave"". Science Scope. Archived from the original on 2009-02-25. Retrieved 2009-03-04.