A light beam with a 70° angle of incidence travels through a medium with an index of refraction of 1.8. The light enters a second medium and has an angle of refraction of 37°. What is the index of refraction of the second medium?

Explanation:

For refraction , the formula is

sin i / sin r = μ₂ / μ₁

where light is travelling from medium 1 to 2 having refractive index of μ₁ and μ₂ . Angle of incidence in medium 1 is i and angle of refraction in medium 2 is r .

Here i = 70°, r = 37°

μ₁ = 1.8 ,μ₂ = ?

sin70 / sin 37 = μ₂ / 1.8

.939 / .602 = μ₂ / 1.8

1.56 =  μ₂ / 1.8

μ₂ = 2.81 .