speed (m/s) = wavelength (m) * frequency (1/s)
v = λf
so, for a given frequency, the velocity is directly proportional to the wavelength.
Get v in air, and then you can figure v in glass.
the light from a helium neon laser has a wavelength of 632 nanometers in air. the same light has a wavelength of 479.2 in glass. the frequency of the light is the same in air and glass. find the speed of the laser light in glass.
2 answers
speed = wavelength * frequency
so, the speeds are in the same ratio as the wavelengths
sglass = sair (wglass / wair)
so, the speeds are in the same ratio as the wavelengths
sglass = sair (wglass / wair)