PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
While kayaking on a sunny afternoon, a student notices a bright, fully horizontally polarized glare reflecting from the surface of a lake. To reduce the glare, the student puts on sunglasses that contain a single ideal linear polarizing filter. The transmission axis of the filter makes an angle of 25∘ with the vertical.
(a) Calculate the percentage of the glare’s initial intensity that reaches the student’s eyes through the sunglasses.
(b) The student rotates the glasses so that the transmission axis makes a different angle with the vertical. Determine the angle (measured from the vertical) that will reduce the intensity of the glare to 5\% of its initial value.
(c) Explain qualitatively why rotating the glasses changes the brightness of the glare but has little effect on the appearance of non-reflected objects such as the kayak’s paddle.