Answer:
Angle of ray makes with the vertical is 62.1 degree
Explanation:
As per the ray diagram we know that the angle of incidence on oil brine interface will be given as
[tex]tan\theta_i = \frac{0.7}{0.98}[/tex]
[tex]\theta_i = 35.5^0[/tex]
now by Snell'a law at that interface we have
[tex]\mu_1 sin\theta_i = \mu_2 sin \theta_r[/tex]
now we will have
[tex]1.52 Â sin35.5 = 1.40 sin\theta_r[/tex]
[tex]\theta_r = 39.12^0[/tex]
now this is the angle of incidence for oil air interface
so now again by Snell's law we will have
[tex]\mu_2 sin\theta_i' = \mu_{air} sin\theta[/tex]
[tex]1.40 sin39.12 = 1 sin\theta[/tex]
[tex]\theta = 62.1^0[/tex]