What is the relationship between water height and standing waves in a tube?

[WhyPrime89]

Homework Statement

A 1.0--tall vertical tube is filled with 20 water. A tuning fork vibrating at 573 is held just over the top of the tube as the water is slowly drained from the bottom. At what water heights, measured from the bottom of the tube, will there be a standing wave in the tube above the water?

Homework Equations

f=m(v/4L), speed of water is 1480 m/s

The Attempt at a Solution

by using the information given we used m= as odd interegers to find the length of the standing waves in the tube. There should be three answers but we can only get one which is .34

 

[chrisk]

The standing wave is set up in the tube between the water interface and the end of the tube. You may be using the speed of sound in water in your calculation. Assume the medium of the standing wave is air.