Wavelength / Frequency
Wavelength λ (m)
5.5000e-7
Frequency f (Hz)
5.4508e+14
Period T (s)
1.8346e-15
Photon energy (eV)
2.254258
Photon energy (J)
3.6117e-19
Spectrum
Visible
FAQ
EM and mechanical waves
What is λ = c/f?
Fundamental relation between wavelength (λ), wave speed (c, in vacuum = 299792458 m/s for light) and frequency (f). Holds for any wave; only c changes in different media.
Photon energy formula?
E = h·f, where h is Planck constant (6.626×10⁻³⁴ J·s). Energy of a single photon, fundamental for quantum phenomena like photoelectric effect.
How are wavelength and frequency related?
Wavelength is the speed of propagation divided by the frequency, so the two are inversely proportional. In a vacuum that speed is the speed of light.
How is the energy of a photon worked out?
By multiplying the frequency by the Planck constant. It is the calculation behind the photoelectric effect, and it explains why ultraviolet light carries more energy than visible light.
Does this hold for sound as well?
Yes, the relation holds for any wave: you only change the speed of propagation, which for sound in air is about 343 metres per second instead of 300 thousand kilometres per second.