Let$$s explore refraction in this problem. Recall that nair $=1,$ nwater $=1\mathrm{.}33$ and

nglass $=1\mathrm{.}5.$

$($a$)$ Calculate the critical incident angle above which total internal reflection occurs

if light is passing from glass to air.

Answer: $41\mathrm{.}8$

$($b$)$ Calculate the critical incident angle above which total internal reflection occurs

if light is passing from water to air.

Answer: $48\mathrm{.}8$