(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Two loudspeakers emit 300 Hz notes. One speaker sits on the ground. The other speaker is in the back of a pickup truck. You hear eight beats per second as the truck drives away from you. What is the truck's speed? (Assume that the speed of sound is 343 m/s.)

2. Relevant equations

These equations could be useful:

change in d= d2-d1, d1 distance is one speaker on the ground, and d2 another speaker on the truck.

Constructive interference: change in d= m*wavelenght, m= 1,2,3,...

Destructive interference: change in d= (m+1/2)* wavelenght, m=1,2,3,...

f(beat)= f1-f2

f(oscillations) = 1/2(f1+f2)

3. The attempt at a solution

I am not sure how to go about this problem. I tried using f(beat) formula but I am stuck. Please help.

Thank you,

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# Homework Help: Interference of Waves from Two Sources and Beats

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