tuning fork and harmonics

[lettertwelve]

1. The problem statement, all variables and given/known data

The frequency of a tuning fork can be found by the method shown in Figure 13-24. A long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. The length of the air column, L, is adjusted by moving the tube vertically. The sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. The smallest value for L for which a peak occurs in sound intensity is 8.00 cm. (Use 330 m/s as the speed of sound in air.)

http://www.webassign.net/sfhs99/13-24.gif

(a) What is the frequency of the tuning fork?
______Hz
(b) What is the value of L for the next two harmonics?
______m
______m

2. Relevant equations

V/4L ????????

3. The attempt at a solution

i tried the V/4L for part b, but nothing works.
i dont know where to even start

[alphysicist]

Hi lettertwelve,

What numbers did you use in your attempts for part b? Did you find the frequencies of the next two harmonics?

[Redbelly98]

Not only what numbers did you use, but did you include units in the calculation?

What did you get when you calculated V/4L, and how do you know (or why do you think) it is wrong?