What is the phase velocity of light in glass if n=1.5 at λ=500nm?
I have used eqn n=c/vp =λ0/λ
1.5 = (3x10^8) / vp
vp = (3x10^8)/1.5
I'm not entirely sure if the equation I have used is the correct one. It does not use the λ=500nm as given in the question.