Divers with Flashlights

Refraction and Snell's Law

A diver shines a flashlight upwards from beneath the water at a 42.5 degree angle to the vertical. At what angle does the beam of light leave the water?

Snell’s law:

sin(?_r)/sin(?_i)=n_i/n_r

sin(?_r)=n_water sin(?_i)

?_r=1.3 sin(?_i)

?_r=61.4^o