Ahorizontal beam of unpolarized light is incident on a stack of three polarizing filters with their polarization axes oriented, in sequence, 30◦, 60◦ and 90◦ clockwise from the vertical. the intensity of the light emerging from the stack is measured to be 275 w/m2. what is the intensity of the emerging light (in w/m2) if the middle polarizing filter is removed?

Acertain sound is recorded by a microphone. the same microphone then detects a second sound, which is identical to the first one except that the amplitude of the pressure fluctuations is larger. in addition to the larger amplitude, what distinguishes the second sound from the first one? it is perceived as higher in pitch. it is perceived as louder. it has a higher frequency. it has a longer wavelength.