Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 10⁸ m s⁻¹.

Refractive index of a medium n_m is given by,

Speed of light in vacuum, c = 3 × 10⁸ m s⁻¹

Refractive index of glass, n_g = 1.50

Speed of light in the glass,