Musicians can use beats to tune their instruments. One flute is properly tuned and plays the musical note A at exactly 440 Hz. A second player sounds the same note and hears that her instrument is slightly "flat" (i.e., at too low a frequency). Playing at the same time as the first flute, she hears three loud-soft-loud beats per second. By how much she must shorten her flute to bring it into tune? Assume a speed of sound of 350 m/s.