Final answer:
Light reflected from the water's surface is completely polarized at Brewster's Angle, which for water is approximately 53.1 degrees relative to the normal to the surface.
Step-by-step explanation:
The phenomenon in which light reflected from a surface becomes completely polarized at a certain angle is known as Brewster's law. According to this law, the angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent surface, without any reflection, is called Brewster's Angle. For water, Brewster's Angle can be calculated using the refractive index of water, which is typically around 1.333. The formula to find Brewster's Angle (θB) is given by tan(θB) = n, where n is the refractive index of the water.
Using the formula, we get tan(θB) = 1.333. Solving for θB yields an angle of approximately 53.1 degrees. Therefore, light reflected from the water's surface will be completely polarized at an angle of 53.1 degrees relative to the normal to the surface.