A loudspeaker having a diaphragm that vibrates at 1250 Hz is traveling at 80.0 mi. directly toward a pair of holes in a very large wall in a region for which the speed of sound is 344m/s. You observe that the sound coming through the openings first cancels at ± 12.7° with respect to the original direction of the speaker when observed far from the wall. (ii) How far apart are the two openings?
(b) At what angles would the sound first cancel if the source stopped moving?