A student wishes to lower the volume of music coming from a loudspeaker by placing…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Waves Sound and Physical Optics · Waves Sound and Physical Optics
Problem
A student wishes to lower the volume of music coming from a loudspeaker by placing two linear polarizing sheets at right angles in front of it, similar to the way crossed polarizers block light. Which of the following best predicts the outcome?
(a) The sound intensity will be reduced by half because one of the crossed polarizers partially absorbs vibrations in all directions.
(b) The sound intensity will drop to near zero because crossed polarizers always block wave energy, regardless of wave type.
(c) The sound intensity will remain essentially unchanged because sound waves are longitudinal and cannot be polarized.
(d) The sound will convert to a transverse form after the first polarizer, so a measurable but incomplete reduction in intensity will occur at the second polarizer.