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Wavelength Formula
A Wavelength Formula is a mathematical equation used to calculate the length of a wave.
The most common wavelength formula is the following:
λ = c/f
Where λ is the wavelength, c is the speed of light, and f is the frequency.
About the Topic
The speed of light is a constant, so the only variable in this equation is the wavelength. The frequency is directly related to the wavelength; the frequency increases as the wavelength gets shorter.
This relationship can be seen in the following equation:
f = c/λ
So, if we know the speed of light and the frequency, we can calculate the wavelength.
The speed of light is 299,792,458 meters per second. The frequency is the number of waves that pass a point in a given period, usually expressed in Hertz (Hz). One Hz is equal to one wave passing per second.
Solved Examples
For example, if we have a wavelength of 500nm (500 nanometers), we can plug that into the first equation and solve for the frequency:
f = c/λ
f = 299,792,458 m/s / 500 nm
f = 599,584,916 Hz
This is a very high frequency; most of the visible light spectrum falls between 400 nm and 700 nm, ranging from about 400 THz (terahertz) to 790 THz.
How do you calculate wavelength from frequency?
If we know the speed of light and the wavelength, we can also calculate the frequency.
For example, if we have a wavelength of 700 nm (700 nanometers), we can plug that into the second equation and solve for the frequency:
f = c/λ
f = 299,792,458 m/s / 700 nm
f = 428,284,921 Hz
This is a slightly lower frequency than the previous example; most of the visible light spectrum falls between 400 nm and 700 nm, ranging from about 400 THz (terahertz) to 790 THz.
The wavelength formula is a simple and easy way to calculate the length of a wave. It is important to remember that the speed of light is a constant, so the only variable in this equation is the wavelength. The frequency is directly related to the wavelength; the frequency increases as the wavelength gets shorter.
This relationship can be seen in the following equation:
f = c/λ
So, if we know the speed of light and the wavelength, we can calculate the frequency. And vice versa, if we know the speed of light and the frequency, we can calculate the wavelength.
