Problem: Determine the quantity of resonant frequencies that a 1024 Hz tuning fork will have in a 1m long tube with an adjustable water level. Find the length of the air column for each frequency. Assume the speed of sound is 344m/s. Solution: The resonant frequencies are odd integer multiples of the fundamental so, f=(2n-1)f' (where f' is the 1st resonant, n the number of nodes, and f is the nth resonant frequency) f=(2n-1)v/[itex]\lambda[/itex] =(2n-1)v/(4l) = [(n-1/2)v]/(2l) Solving for l, l=[(n-1/2)v]/(2f) Substituting values of n into the equation until l > 1m, n=1 l=8.4cm n=2 l=25.2cm n=3 l=42.0cm n=4 l=58.8cm n=5 l=75.6cm n=6 l=92.4cm Plugging in n=7 yields a length of 1.08 m, so the wave is no longer within the tube. Therefore there are 6 resonant frequencies. Is this correct?