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Show Close Calculations. The slow flapping of a butterfly's wings produces no sound. When the movements are rapid, a noise is produced, pro-duced, which increases with the number num-ber of vibrations. Thus the house fly. which produces the sound of F, vibrates its wings 21.120 times a minute, or 335 times a second, and the bee, which makes a sound of A, as many 26,400 times, or 440 times a second. A tired bee hums on E, and therefore, according accord-ing to theory, vibrates its wings only 330 times a second. |