Standing Wave in Closed Tubes Lab

[dragahlak]

1. http://img856.imageshack.us/i/scanpic0001.png/
using tuning forks, you're supposed to choose 7 notes and find the frequency and length then find an approx speed for sound. we did this with logger pro and a USB microphone device and glass tubes. i plugged in my data to this eq'n: fn = (nv)/(4L) but velocity didn't look right and not even close to 343. the teacher said the Hz plugged in comes from the peak on the chart recorded on Logger Pro and Length comes from the surface of the water to the top of the inside beaker

2. fn = (nv)/(4L)
3. for E 320 Hz. i got 1933 Hz and .235 m
what's n supposed to be? i think it has to be odd
if n = 1 i get v = 1817 m/s

 

[jbsteele]

if n = 3 i get v = 1714 m/s if n = 5 i get v = 1657 m/s N is the number of the harmonic that you are measuring. Since you are measuring the frequency of a tuning fork, the N value should be an odd number since the tuning fork produces odd harmonics.