A flashlight beam is directed at a swimming pool in the dark at an angle of 46° with respect to the normal to the surface of the water. What is the angle of refraction of the beam in the water? (The refractive index for water is 1.33.)

Answer: the angle of refraction of the beam is 33 degrees

Explanation:

Given that the

Incident angle I = 46°

Refractive index n = 1.33

According to Snell law,

Refractive index = ratio of sine of incidence to the sine of reflection.

That is

n = sin i/sin r

Substitute n and I Into the formula above.

1.33 = sin 46/sin r

Make sin r the subject of the formula

Sin r = sin 46/1.33

Sin r = 0.540

Find the sine inverse of r

r = sin^-1 (0.540)

r = 32.7 degree

r = 33 degree approximately