Tuning Fork Lab

Guiding Question: How does the density of a material affect the properties of sound travelling from a tuning fork?

Hypothesis: I think that the denser the material the object the louder the sound is going to be.

Materials:

- Tuning fork C256

- Hollow wooden box

- Desk

- Wall

- Metal Railing

- White board

- Notebook and Pencil to record observations

Procedure:

1. Gather all the materials above.

2. Take your tuning fork, and hold it by the side with only one piece of metal. Gently bang it on the side of a desk. Place the small piece of metal of your tuning on the desk, and with your ear on the desk, listen to the sound vibrations. Record your observations.

3. Do this for all your other materials.

Data Chart:

Medium	Density	Sound description
Hollow wooden box	0.63g/cm3	Low, buzzy sound
Desk	0.63g/cm3	Low, quiet buzzy sound
Wall	1.1g/cm3	High sound, loudest, short vibrations
Metal railing	8.60g/cm3	Very high, one long, dragged out sound
White board	2.7g/cm3	Higher than wooden box, kind of fuzzy

Data Analysis:

From my data I can see that this was my order of denseness in my mediums; hollow wooden box and desk, wall, whiteboard, and metal railing. This also sort of combines with my observations for each sound, since the least dense materials made lower sounds, and the materials with higher density made higher sounds. The metal railing, the material with the higher density had a very high sound, and according to me it was one long and dragged out sound, with no buzziness or fuzziness. Something weird that I noticed was that the hollow wooden box and the desk both have the same density, but according to my observations the desk had a quieter sound than the hollow wooden box. I later found out that the reason that the two mediums had the same density was that they both were made from oakwood. Perhaps the reason that the desk had a smaller sound was that it was bigger and the waves were more spread out. Otherwise, I might have made unaccurate measurements such as not tapping with the same force on the tuning forks, or possibly having my ear from different distances from the source of the sound.

Conclusion:

Looking at my data, I can conclude that sound travels faster in denser materials than in less dense ones. Also, the higher sounds come from the denser materials. I can see this because my densest material, the metal railing, with a density of 8.60g/cm³ , produced a much higher sound than the wooden box and the desk, which were made of oakwood and had a density of 0.63g/cm³ . This proves that sound travels faster in denser materials. This is probably because since sound is a longitudinal wave it needs a medium to travel through. (otherwise it can’t travel). I think that the more medium the sound had the faster it can travel through it. Therefore, the more compacted the medium is (the more dense it is), the sound can travel more quickly through it. This also means that liquids such as water transmit sound slower than for example rocks, so basically solids can carry sound faster than liquids. This also means that gas would be even harder for sound to travel through, since it’s even less dense. Therefore, sound is heard better travelling through solids than travelling through anything else.

Further Inquiry:

After this experiment, something I’d like to do is try a lab comparing different tuning forks to see which works better. Then we could compare them and see how the sound changes through each one in the same medium. We could also have tried some other mediums, such as glass, the floor or maybe even a laptop, if we do it carefully. Something else that I’d like to do is to try using the tuning forks and recording observations through a liquid, instead of using a solid as a medium. However, we might need special instruments then, since it probably won’t be so easy to hear it. It would also be cool to try sound through a gas, but I don’t know how that’d work either, since you can’t really tap the tuning fork against gas. Well, maybe you could, but it wouldn’t make a sound, or at least one that is hearable to humans.

Sites Used

http://www.wolframalpha.com/