# Homework Help: Destructive interference Sound question

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1. Apr 18, 2015

1. The problem statement, all variables and given/known data
A student enters Best Buy prepared to buy a pair of speakers. Before he does so, he conducts an experiment with them. He places the speakers 4.0 m apart and connects a signal generator to both speakers that produces a single and consistent tone. (constant wavelength and frequency) He then walks to a point that is 2.0 m from one speaker and 2.3 m from the other. At that point he notices a quiet “spot”. If the speed of the sound in the room is known to be 350 m/s, calculate the possible frequencies being played by the speakers.

2. Relevant equations
PD = (n-1/2) λ

3. The attempt at a solution
No idea how to solve.

2. Apr 18, 2015

### paisiello2

How is a quiet spot generated?

3. Apr 18, 2015

PD = path difference, so N would be the nodal line.
I guess quiet spots are generated during points of destructive interference? Am I correct?

4. Apr 18, 2015

### paisiello2

Yes. So now you need to figure out where this is occurring in the problem.