Calle K, Riley, Sophie W, Emily J
4/4/2011

Purpose
We duplicated the work of Jasper W-B, Sascha P, Jackson T, Kim T, and Griffin G-B in 2009 to find how a wine glass produces a regular tone when a finger is rubbed around the rim. After Eva P attempted to recreate their data for further analysis using a slightly different procedure in 2010 and got different, yet equally compelling results, we were curious to see if the earlier group’s data was even duplicable at all. To do this, we followed the procedure and data analysis in their lab report. If we were to reach their same conclusion, we would be reassured that the group did not go wrong in their procedure or analysis

Equipment
Water
Wine glass that holds approximately 600mL
Logger Pro
Microsoft Excel
Microphone
Graduated cylinder
Thin wooden sticks

Procedure
Using completely cleaned and dried equipment; we moistened one finger, and ran it around the rim of the glass. We held the microphone up to the glass, and using an FFT graph in Logger Pro, we stopped our movements once we noticed a clear peak frequency. We recorded the peak frequency, along with the volume and depth of the water. We then added water in 50mL increments, and repeated the process until we reached 600mL. We put the data into Microsoft Excel, graphed the relationship between volume and peak frequency, and then manipulated the data to find the highest correlation coefficient.

Data and Analysis
Volume (mL)
Water Depth (cm)
Peak Frequency (Hz)
0
0
625
50
1.75
605.45
100
2.55
585.94
150
3.50
566.41
200
4.20
546.88
250
4.80
527.34
300
5.50
507.81
350
6.10
480.28
400
6.55
449.22
450
7.35
410.16
500
7.90
351.60
550
8.60
292.70
600
9.00
273.44

Above is the table for the values we collected. Unlike the previous group, we measured not only the volume of water, but also its depth in the glass. The correlation coefficient of Volume v. Frequency was -0.9771.

Frequency^2
Volume^2
Volume^3
ln(Frequency)

390625

0
0
6.43775165
366569.7025
2500
125000
6.40597198
343325.6836
10000
1000000
6.3732174
320820.2881
22500
3375000
6.3393182
299077.7344
40000
8000000
6.3042294
278087.4756
62500
15625000
6.2678455
257870.9961
90000
27000000
6.23010736
230668.8784
122500
42875000
6.17436927
201798.6084
160000
64000000
6.10751275
168231.2256
202500
91125000
6.01654733
123622.56
250000
125000000
5.86249417
85673.29
302500
166375000
5.67814819
74769.4336
360000
216000000
5.61108222

We then altered the data in the same way the previous group did, and found convincing correlation coefficients

Vol v Freq
-0.9771
Vol v Freq^2
-0.9934
Vol^2 v Freq
-0.9939
Vol^3 v Freq
-0.9715
Vol v lnFreq
-0.9493
Conclusion

We too found convincing data though ours varied from both groups. Further research must be conducted to achieve a positive conclusion.