Question

Two speakers 14m apart are emitting tones at a frequency of 1020 Hz. what is the closest distance (in m) from one speaker, along the line connecting the speakers, at which the sound intensity will be zero?

Answers

bobpursley
The closest point?
let a be the distance, so 14-a is the other distance.

Now to be zero amplitude, these two waves have to be 1/2 Lambda different.

Lambda= 340m/1020=.333m
lambda/2= .167m

well, (14-a)/.167-.5=a/.167

14-a-.0833=a
a=6.958m

checking this (I don't believe it)
6.958/.167=41.66 half wavelengths
(14-6.958)/.167=42.17 half wavelengths

the difference is indeed half wavelength.

check my work, I am still wondering.

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