Question

What will be the speed of light in water if its speed is 3 into 10 power 8 in vacuum and refractive index of water is 4 by 3? With FORMULA

Answer 1

Given refractive index(n)=4/3
And speed of light in vacuum=3×10⁸ m/sec
Speed of light in water=?
Refractive index=Speed of light in vacuum/speed of light in water
⇒4/3=(3×10⁸)/x
⇒x=3×10⁸×3/4
⇒x=2.25×10⁸m/sec
Therefore,speed of light in water is 2.25×10⁸m/sec.

Answer 2

Refractive index of water=4/3
Speed of light in vaccum=3*10^8
Refractive index(n)=speed of light in vaccum(c)/speed of light in given media i.e. water(v)
n=c/v
4/3=3*10^8/v
v=(3*10^8)*3/4
Speed of light in water=2.25*10^8 or 225*10^6