Question

A light ray in air hits a piece of quartz, at a 39.0 deg angle. Inside the quartz, the light slows down to 2.06 x 10^8 m/s. At what angle does the light travel in quartz? (Hint - water n =1.33, air n = 1.00) (answer will be in degrees)

• note : this question has been posted before on chegg and answer given was 1.456 but that shows to be not the right answer.

Answer 1

here,

the angle of incedence , i = 39 degree

speed of light in air , v1 = 3 * 10^8 m/s

speed of light in quartz , v2 = 2.06 * 10^8 m/s

let the angle of refraction be r

using snell's law

sin(r)/sin(i) = v2 /v1

sin(r) /sin(39) = ( 2.06 * 10^8)/(3 * 10^8)

solving for r

r = 25.6 degree

the angle of refraction is 25.6 degree