Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....

Period and frequency of a fly’s wing-beats

A Victorian parlor trick was to listen to the pitch of a fly's buzz, reproduce the musical note on the piano, and announce how many times the fly's wings had flapped in one second. If the fly's wings flap, say, 200 times in one second, then the frequency of their motion is f=200/1 s=200 s-1. The period is one 200th of a second, T=1/f=(1/200) s=0.005 s.

Last Update: 2009-06-21