Question

If the difference in velocities of light in glass and water is 2.7 x 10⁷ m/s, find the velocity of light in air. (Refractive index of glass = 1.5, Refractive index of water = 1.333)

Answer 1

`u=C/v`

`:.v_g=C/mu_g`

`v_w=C/mu_w`

`:.v_w-v_g=C/mu_w-C/mu_g`

`2.7xx10^7=C(3/4-2/3)`

`2.7xx10^7=C((9-8)/12)`

C = 2.7x12x10⁷

=3.24x10⁸m/ s