Final answer:
Light reflected from a water surface is completely polarized when it hits the water at Brewster's angle, which is about 52.6 degrees for water with an index of refraction of 1.3.
Step-by-step explanation:
The student is asking about the specific angle at which light reflected from a water surface will be completely polarized. This phenomenon is described by Brewster's Law, which states that light is fully polarized when the reflected and refracted rays are perpendicular to each other. The index of refraction of water (given as μ) is 1.3 in this scenario.
The angle of incidence at which this occurs is called the Brewster's angle (θB), and can be found using the formula:
θB = arctan(μ)
For water with μ = 1.3, the calculation would be:
θB = arctan(1.3)
Now we need to calculate this value:
θB ≈ arctan(1.3) ≈ 52.62°
Thus, light will be completely polarized when it hits the water surface at an angle of approximately 52.6 degrees.