Question

the refractive index of glass and water wrt air is 3/2 and 4/3. the speed of ligt in glass is 2*10^8. find speed of light in water.

Answer 1

ng=3/2.
nw = 4/3
vg= 2*10^8
ng = c/vg
3/2 = c/ 2*10^8
3/2/2*10^8 = c
3*2*10^8/2 = c
3*10^8 =c
nw=c/ vw
4/3= 3*10^8/vw
4*3*10^8/3 = vw
4*10^8 = vw