- #1

Taniaz

- 364

- 1

## Homework Statement

Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is L = 2.00 m to the right of speaker A. The frequency of the sound waves produced by the loudspeakers is f = 206 Hz. Consider point P between the speakers and along the line connecting them, a distance x to the right of speaker A. Both speakers emit sound waves that travel directly from the speaker to point P. a) For what values of x will destructive interference occur at point P? b) For what values of x will constructive interference occur at point P?

## Homework Equations

Path differences for destructive (n + 1/2 λ) and constructive interference.(n λ)

## The Attempt at a Solution

For part a) xa-xb = x-(L-x) = 2x-L = (2l -1) λ/ 2, where l is an integer and then they got x = L/2 + (2l - 1)λ / 4

I don't understand how they got (2l -1) λ / 2 and x = L/2 + (2l - 1)λ / 4

For b) xa-xb= 2x-L = lλ so x = L/2 + l/2 λ

For a I would have simply just done it as 2x-L = λ/2 so x = L/2 + λ/4