How to Calculate Frequency
- 1). Find the fundamental constants using the links shown below in \"Resources.\"<br />Speed of light (c) =299,792,458 m/s. Planck constant (h) =4.13566733E?15 eV s (1E-15 denotes "10 in power -15").
- 2). Divide energy by the Planck constant to calculate frequency. Frequency(Hz) = Energy/h=Energy/4.13566733E?15 eV s. Energy needs to be expressed in "electron volt (eV)" units. For example, to calculate the wavelength of the ultraviolet (UV) light with the energy 4.5 eV: Frequency =4.5 eV/4.13566733E?15 eV s=1.09E15 Hz=1,090 THz. Note the prefix "Tera(T)-" implies the magnitude of 1E12 (see resources).
- 3). Divide the speed of light by the wavelength to calculate frequency. Frequency (Hz) = c/ wavelength(m) =299,792,458 (m/s)/frequency. For example, to calculate the frequency of the visible red light with the wavelength of 700 nanometers (nm): 700 nm equals to 7E-7 m. Wavelength=299,792,458 (m/s)/7E-7m= 4.28E14=428 THz.
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