A flutist assembles her flute in a room where the speed of sound is 340 m/s. When she plays the note A, it is in perfect tune with a 440 Hz tuning fork. After a few minutes, the air inside her flute has warmed to where the speed of sound is 343 m/s.

How many beats per second will she hear if she now plays the note A as the tuning fork is sounded?

Explanation:

Beat results due to difference in the frequency of tuning fork and sound produced by the flute at higher temperature.

frequency of tuning fork = 440 Hz

apparent frequency of flute at higher temperature = 440 x (343 / 340)

= 444 Hz (approx )

No of beats heard = 444 - 440 = 4 beats per second.  

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered