- #1
Puchinita5
- 183
- 0
Homework Statement
In Fig. 17-35, sound with a 46.4 cm wavelength travels rightward from a source and through a tube that consists of a straight portion and a half-circle. Part of the sound wave travels through the half-circle and then rejoins the rest of the wave, which goes directly through the straight portion. This rejoining results in interference. What is the smallest radius r (cm) that results in an intensity minimum at the detector? (Take the speed of sound to be 343 m/s.)
Homework Equations
http://edugen.wiley.com/edugen/courses/crs1650/art/qb/qu/c17/pict_17_34.gif
The Attempt at a Solution
i have the solution...what i don't understand is WHY the path length difference equals 23.2? don't see how or why it's half the wavelength?