Answer:
The critical angle is 41.8°.
Explanation:
The critical angle is [tex]\theta_1[/tex] for which the angle of refraction [tex]\theta_2[/tex] is 90°. From Snell's law we have
[tex]n_1sin (\theta_1 ) = n_2 sin(\theta_2)[/tex]
[tex]n_1sin (\theta_1 ) = n_2 sin(90^o)[/tex]
[tex]sin (\theta_1 ) = n_2/n_1,[/tex]
[tex]\theta_1 = sin^{-1}(\dfrac{n_2}{n_1} ).[/tex]
Putting in [tex]n_2 =1.00,[/tex] and [tex]n_1 = 1.50[/tex] we get:
[tex]\theta_1 = sin^{-1}(\dfrac{1.00}{1.500} ),[/tex]
[tex]\boxed{\theta_1 = 41.8^o}[/tex]
Thus, the critical angle is 41.8°.