Answer: speed of light in solid = 1.88 * 10^8 m/s
Frequency is constant
Explanation: The relationship between the velocity of light wave and wavelength is given by the formulae below
V = fλ
During refraction, the frequency of light is constant, thus we have that
V = kλ which implies that velocity is proportional to wavelength.
Hence, we have that
v1/ λ1 = v2/ λ2
Where v1 = velocity of light in air = 3 * 10^8 m/s
v2 = velocity of sound in solid
λ1 = wavelength of light in air = 670nm
λ2 = wavelength of light in solid = 420nm
By making v2 subject of formulae, we have that
v2 = v1 * λ2/ λ1
v2 = 3 * 10^8 * 420nm/ 670nm
v2 = 3 * 10^8 * 0.6268
v2 = 1.88 * 10 ^8 m/s
b)
During refraction the frequency of light wave is constant this is because light consist of photons which has energy. it energy needs to be constant and for energy (E=hf) to be constant, frequency would be constant too.