Question

A ray of light enters glass of refractive index 1.5 from air. If the speed of light in vacuum is 3×10 to the power 8m/s, what is the speed of light in glass

Answer 1

n = c/v

n(glass) = 3 x 10^8/ speed of light in glass

speed of light in glass = 3 x 10^8/1.5

= 2 x 10^8 m/s

:-)