Question

8. The acoustical system shown in the figure is driven by a speaker emitting sound of frequency 620 Hz. Take Vair = 340 m/s. (a) If the upper U-shaped tube is 1.10 m long and the lower U- shaped tube is 1.37 m long, can the person in the picture hear the sound? Why? (b) To change the status (either from louder to softer or from softer to louder), how much the length of the lower U- shaped tube needed to be increased?

Answer 1

path difference of sound 0x = 1:87-11 0.27m. wave length of found ware A=4 = 340 620 7=0.54 m. here ax=) 2 = 1/2 it is a lase case of destructive interference which means that sound will be softer To make it constructive interference, path difference wavelength. be should equal to (Al= p = 0.29m] = loweo tube should be increased by this much length.