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## Homework Statement

https://tycho-s.phys.washington.edu/cgi/courses/shell/common/showme.pl?courses/phys123/spring08/homework/01b/twospeaker_INT/02.05.gif [Broken]

(if image doesn't show up...it is a right angle triangle with S1 at the right angle, 4m between it and O and 3m between S1 and S2)

The two speakers at S1 and S2 are adjusted so that the observer at O hears an intensity of 4 W/m2 when either S1 or S2 is sounded alone. They are driven in phase (at the speakers) with various frequencies of sound. Assume that the speed of sound is 325 m/s.

a) Find the three lowest frequencies, f1 < f2 < f3, for which the observer at O will hear an intensity of 16 W/m2 when both speakers are on.

b) Find the three lowest frequencies, f1 < f2 < f3 , for which the observer at O will hear no sound when both speakers are on.

c) Find the lowest frequency for which the observer at O will hear an intensity of 8 W/m2 when both speakers are on.

d) Find the lowest frequency for which the observer at O will hear an intensity of 4 W/m2 when both speakers are on.

## Homework Equations

I think these...

f=v/[tex]\lambda[/tex]

Intensity= energy/tA

I also need to figure out the phase difference but not sure what formula

## The Attempt at a Solution

so far I know that I need to find the path length difference between the two speakers to the observer...which is 1m. From that I need to find the phase difference which will give me the intensity. How to do this I am clueless on. Then I need to find the wave length from the difference between the two and from that I can find the frequency. (at least this is what I am thinking...but its not working! and I can't figure out the phase difference)

Any help appreciated!

## Homework Statement

## Homework Equations

## The Attempt at a Solution

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