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In preparation for a backyard concert, you set up two stereo speakers on your fr

ID: 1383731 • Letter: I

Question

In preparation for a backyard concert, you set up two stereo speakers on your friend?s back patio as shown in the diagram (view from above). You are concerned that at some locations the listeners won?t
be able to hear certain frequencies

as a result of interference. Take the speed of sound to be 343 m/s. Ignore the reflection of sound from the house, trees, etc. Assume the speakers are in phase.

If you sit in the middle of the bench, which frequencies will interact constructively? Which will interact destructively?

If you sit in the lawn chair on
the left, what will be the
lowest frequency lost to destructive interference?

speakers 10 m 3 m chairchair chair chair 8 m 3 m Bench 5 m

Explanation / Answer

if ypu seat in the middle of the bench- frequency= v = f * lamda

f= 343/ 5 =68.6 Hz

all multiples of this frequency will unteract constructively.

lost frequency lost= 343/3 =114.3Hz