Question

Two identical loudspeakers are driven in phase by a common oscillator at 750 Hz and face each other at a distance of 1.24 m. Locate the points along the line joining the two speakers where relative minima of sound pressure amplitude would be expected. (Take the speed of sound in air to be 343 m/s. Choose one speaker as the origin and give your answers in order of increasing distance from this speaker. Enter 'none' in all unused answer boxes.)

Answer 1

0.2286 m, 0.686 m and 1,143 m

therefore we see that there is respect even where the intensity is minimal

Step-by-step explanation:

Destructive interference to the two speakers is described by the expression

Δr = (2n +1) λ/2

where r is the distance, λ the wavelength and n an integer indicating the order of the interference

let's locate the origin on the left speaker

let's find the wavelength with the equation

v = λ f

λ = v / f

we substitute

Δr = (2n + 1) v / 2f

let's calculate for difference values ​​of n

Δr = (2n +1) 343/(2 750)

Δr = (2n + 1) 0.2286

we locate the different values ​​for a minimum of interim

n Δr (m)

0 0.2286

1 0.686

2 1,143

therefore we see that there is respect even where the intensity is minimal