Question

)The refractive index of glass and water with respect to air are 3/2 and 4/3 respectively. if the speed of light in glass is 2×10 8^ m/s, find the speed of light in water.​

Answer 1

refractive index = $\frac{c}{v}$

c = speed of light in air

v₁ = speed of light in glass

v₂ = speed of light in water

Now,

$\frac{3}{2}$ = $\frac{c}{2*10^8}$

⇒ c = $\frac{3*2*10^8}{2}$

⇒ c = 3 × $10^{8}$

∴ $\frac{4}{3}$ = $\frac{3*10^8}{v_{2} }$

∴ $v_{2}$ = $\frac{3*3*10^8}{4}$

∴ $v_{2}$ = $\frac{9*10^8}{4}$