Question

howdy, just cant seem to get this question, can anyone express this question in words i can get?! thanks

A sound wave of wavelength 0.8 m divides into two equal parts that recombine to interfere constructively, with the original difference between their path lengths being |r2|-|r1| = 0.8 m. Rank the following situations according to the intensity of sound at the receiver from the highest to the lowest. Assume the tube walls absorb no sound energy.

*The figure is two U shaped pipes with them shaped like opposite horseshoes, and at the junctions where they meet are holes for the sounding device and the other for the listener

Answer 1

a. If the tube is moved by 0.1 m, r2 increases by 0.2m, so r2-r1 is now 0.1m. Therefore lambda is (2pi/0.8)(0.1)=2.5pi
--> Intensity=I cos squared(2.5pi/2)

You pretty much d that for each one and you get d>a=c>b