Question

A light ray falling at an angle of 45° with the surface of a clean slab of ice of thickness 1.00 m is refracted into it at an angle of 30°. Calculate the time taken by the light rays, to cross the slab. Speed of light in vacuum - 3 x 108 m/s.

Answer 1

hey there is answer !!

I hope you help !!!



Dear student,
μ=sinisinr=sin45sin30=12√1/2=2‾√=1.41μ=cvv=1.41×3×108=4.23×108m/st = d/v=1 cm/423×108 cm/st=0.0023×10−8 
Regards

Answer 2

Given :

Angle of incidence= i= 45°

angle  of refraction =r= 30°

μ= sin i/ sin r

as we know that μ=C/V

sin 45/ sin 30 =3 x 10 ⁸ / v

1/√2/ 1/ 2= 3 x 10 ⁸ / v

v= 3 x 10 ⁸ / 2 m/s

Distance travelled by light in slab is

x= 1m / cos 30 = 2/√3

time taken = (2/√3) x[√2/ 3 x 10⁸]

=5.4 x 10 ⁻⁹ s

∴  time taken by the light rays, to cross the slab is 5.4 x 10 ⁻⁹ sa