A flashlight beam strikes the surface of a pane of glass (n=1.56) at a 71° angle to the normal. What is the angle of refraction? Express your answer using two significant figures

The angle of refraction is 37°.

Explanation:

let n1 be the refractive index of glass and n2 = 1.0 be the refraction index of air, θ be the angle of incidence, ∅ be the angle of refraction.

then, according to Snell's law:

n1*sin (∅) = n2*sin (θ)

sin (∅) = n2*sin (θ) / n1

= (1.0) (sin (71°)) / (1.56)

= 0.606101651

∅ = 37°

Therefore, the angle of refraction is 37°.