Question

3. The refractive index of water is 4/3. The speed of light in water is
A) 2.25 x 10 m/s
B) 2 x 10 m/s C) 3 x 10 m/s
D) 1.90 x 10 m/s​

Answer 1

Answer:

A 2.25 x 10^8 m/s

Explanation:

Given,

Refractive index of water = 4/3

As we know speed of light in vacuum = 300 million m/s = 3× 10^8m/s

speed of light in water = ? we suppose is x

Refractive index of water = Speed of light in vacuum / Speed of water

4/3= 3×10^8/x ( cross multiplication)

4x= 3×3×10^8

4x=9×10^8

x=9×10^8/4

x= 2.25×10^8m/s

so speed of light in water is 2.25×10^8m/s

I hope it's helpful to you