# Destructive Interference

sreya

## Homework Statement

Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. The frequency of the waves emitted by each speaker is 172 Hz. You are 8.00 m from speaker A. Take the speed of sound in air to be 344 m/s.

What is the closest you can be to speaker B and be at a point of destructive interference?

## Homework Equations

$f = \frac{v}{\lambda}$
$\frac{\Delta L}{\lambda} = .5,1.5,2.5,...$

## The Attempt at a Solution

$\lambda = 344/172 = 2$

$1/2 = .5 => Ans:$1m

The odd thing is that it tells you the distance you are from A but wants to know how close you can get to B but you don't know the distance between the two.

The answer is 1, since that would give you 1/2 = .5 but that seems like to me that you're 1m away from A, since we don't know how close we are to B