Tuning Fork Resonance

Tuning Fork Resonance

Abstract:

The purpose of this experiment was to find the first harmonics of certain tuning forks by listening for their resonance in a PVC tube. The materials we needed for this experiment were an assortment of tuning forks, a rubber mallet, a 1000 mL graduated cylinder, a hollow PVC pipe, a meter stick, and enough water to fill the graduated cylinder. Katelyn and I filled the graduated cylinder with water, and then PVC pipe in it. We then took one of the tuning forks and struck it with the rubber mallet and held it over the top of the PVC pipe. We then would move the tuning fork and PVC pipe up and down within the graduated cylinder until we heard the resonance. Then we would take the meter stick and measure from the top of the water level to the top of the PVC pipe. This gave us the fundamental frequency. We then repeated this for the rest of the tuning forks. In order to find the entire wavelength, we had to times the distance of the water level to the top of the PVC pipe by 4. My experimental value/ slope of my graph is 360 m/s. My theoretical value is 344 m/s. My percent error is 7.22%

Results:

Slope/Experimental Value: 360 m/s

Theoretical Value: 344 m/s

Percent Error: 7.22%

Discussion:

1. Katelyn and I were able to find the second resonance. The relationship between to two is that the second resonance is almost 4 times the height of the first. It’s almost like it’s a full wavelength. My prediction for the next resonant is at 61.20 cm.

2. My hypothesis was that the bigger tuning fork frequency it had, the smaller air column it would have. My variables were the tuning forks and my controls were my PVC pipe and the graduated cylinder with water. My results did support my hypothesis.