Question

The refractive index of glass is 1.50 and the speed of light in air is 3x 100 m/s. Calculate the speed of light in glass.


*full explanation required*​

Answer 1

Refractive index = velocity of light in vaccuum/velocity of light in medium

1.50= 3*10^8/v

v = 2*10^8 m/s

Answer 2

$\small \mathsf{ \color{purple}{Refractive \: index \: of \: a \: medium \: (nm)}}$ =

$\small \mathsf{ \color{green}{Speed \: of \: light \: in \: vacuum/ \: Speed \: of \: light \: in \: the \: medium}}$

$\small \mathsf{ \color{pink}{Speed \: of \: light \: in \: vacuum \: (c) = 3 × 108 m/s}}$

$\small \mathsf{ \color{pur}{Refractive \: index \: of \: glass \: (ng) = 1.50}}$

Speed of light in the glass (v) = Speed of light in vacuum/ Refractive index of glass

= c/ng

$\small \mathsf{ \color{blue}{=3 × 108/1.50 = 2x 108 ms-1.}}$