A section of drainage culvert 1.23 m in length makes a howling noise when the wind blows across its open ends. Determine the frequencies of the first three harmonics of the culvert if it is cylindrical in shape and open at both ends. Take v = 343 m/s as the speed of sound in air. f1,2,3 = 139, 279, 418 Hz respectively. ► Why do larger animals produce deeper (lower frequency) sounds? Why does inhaling helium gas make you talk at a higher pitch (higher frequency sound)?

A section of drainage culvert 1.23 m in length makes a howling noise when the wind blows across its open ends. Determine the frequencies of the first three harmonics of the culvert if it is cylindrical in shape and open at both ends. Take v = 343 m/s as the speed of sound in air. f1,2,3 = 139, 279, 418 Hz respectively. ► Why do larger animals produce deeper (lower frequency) sounds? Why does inhaling helium gas make you talk at a higher pitch (higher frequency sound)?