Answer :
Answer:
The answer is "[tex]\bold{51.31^{\circ} \ and\ 33.77^{\circ}}[/tex]"
Explanation:
Please find the graph in the attachment.
For point a:
Calculating the total internal reflection:
[tex]\sin(90-\theta_c) = \frac{n_1}{n_2}\\\\\cos?_c = \frac{n_1}{n_2}\\\\[/tex]
Therefore the [tex]n_1[/tex] is the refractive index in the air medium that is = 1.00
[tex]n_2[/tex] = refractive index of medium = 1.60
[tex](90 - ?_c )[/tex] =incident angle
So,
[tex]?_c = 51.31^{\circ}[/tex]
For point b:
When the pipe is immersed into the water then the equation is:
[tex]1.6\times \sin(90-?)=1.33\times \sin 90\\\\?_c = 33.77^{\circ}[/tex]
