Question

1. Light travels from air into water. If the angle of refraction is 30˚, what is the angle of incidence?

2. A ray of light in air strikes a block of quartz at an angle of incidence of 30˚. The angle of refraction is 20˚. What is the index of refraction in quartz? 

Answer 1

$n=\frac{\sin\alpha}{\sin\beta}=1.46.$