Sound with a 29 cm wavelength travels rightward from a source and through a tube that consists of a straight portion and a half-circle. Part of the soundwave travels through the circle and rejoins the the rest of the wave which goes directly through the straight portion. This rejoining results in interference. What is the smallest radius r (in cm) that results in an intensity minimum at the detector. The maximum destructive interference will occur when the difference in the distance travelled by the two waves is 1/2 of a wavelength. To solve this problem express the difference in the distance travelled by the two waves as a function of r and set this amount equal to 1/2 of a wavelength.

Sound with a 29 cm wavelength travels rightward from a source and through a tube that consists of a straight portion and a half-circle. Part of the soundwave travels through the circle and rejoins the the rest of the wave which goes directly through the straight portion. This rejoining results in interference. What is the smallest radius r (in cm) that results in an intensity minimum at the detector. The maximum destructive interference will occur when the difference in the distance travelled by the two waves is 1/2 of a wavelength. To solve this problem express the difference in the distance travelled by the two waves as a function of r and set this amount equal to 1/2 of a wavelength.