Question

the refractive index of water is 4/3.how much time will light travel through a water column of length 500m

Answer 1

Take refractive index is n=$\frac{4}{3}$

In medium ,
velocity is v=$\frac{n}{n_{1}}$c
Where c is speed of light equall to 3 × 10^8

$n_{1}$ is refractive index of air.
$n_{1}=1$

So,
v=$\frac{4}{3}×3×10^{8}$
$v = 4×10^{8}$

Distance=vt
500=vt

$t=125x×10{-8}$

So light will take $125×10{-8}$ seconds
to travel through water column of 500 mts

Answer 2

Dear Student,

◆ Answer -

t = 2.222×10^-6 s

● Explanation -

# Given -

n = 4/3

s = 500 m

# Solution -

Velocity of light through water is given as -

v = c / n

v = 3×10^8 / (4/3)

v = 2.25×10^8 m/s

Time taken by light to travel through 500 m is -

t = s / v

t = 500 / 2.25×10^8

t = 222.2×10^-8

t = 2.222×10^-6 s

Hence, time taken by light to travel 500 m column is 2.222×10^-6 s.

Thanks dear. Hope this helps you...