The tuning fork sound lab

The sound 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 objects which have a higher density will not transfer sound as well as the objects with lower density will. This is because the objects which are denser have particles that are more packed together, which prevent the longitudinal waves of sound from travelling as easily, as they do in mediums where the particles are less packed, and the density is lower.
Exploration: For this lab there are several materials that I used. Firstly, I used a tuning fork, which was 341.3 F. The materials that I did the lab on were the bin (plastic), the whiteboard (aluminum), table (oak wood), window (glass), cardboard textbook, as well as plastic bottles.

Step 1. Choose a tuning fork, and then choose the materials with which you would like to test the sound on.
Step 2. Tap the tuning fork on the table, or any other stable object, and hold the opposite end to the object that you are testing.
Step 3. Hold your ear to the object that you are testing, and listen to the sound.
Step 4. Describe the sound that you heard, including the pitch, the loudness, etc.

Controlled variable: The tuning fork, and the force we apply, as well as the temperature we did the lab in.
Manipulated variable: The variable we changed was the different objects we used, and the different materials we used.
Responding variable: When we combine the two variables above, the different result we would get is the pitch, loudness and even intensity of the sound waves.

Record and Analyze: Below you can find the information table, where we recorded all our observations.

I see that the sound traveling only partially gets affected by the density. Our observations are also influenced by how far from the tuning fork I am, as well as how loud I hit the tuning fork, etc. All of those variables can affect what we hear, and what we observe.

Conclusion: From the data that I have collected, I can conclude that the density only partially affects what happens to the sound, and how sound travels. It is very difficult to keep the force the same, because you never know how hard you hit the tuning fork the previous time. My hypothesis was correct, but, as I said above, it was very hard to make this lab completely fair. I can also conclude that it is not very easy to write about the pitch and the loudness for each material. Sometimes, the pitch could be very high, and the loudness quite faint. This made it quite difficult to interpret the data.

Further Inquiry: As I said above, I think there were many places for error, which we didn’t necessarily see at first. We didn’t pay much attention to the force we applied, and I think that is something we should have done. Also, it was hard to control the temperature, so we never really knew whether the classroom is colder or warmer then it used to be the previous class. From the data, I can see that density is not everything that affects the way that sound travels, and why it has higher or lower pitch, different loudness, etc. One of the questions that I have unanswered after completing this lab is what are some other factors that affect the traveling and the properties of longitudinal sound waves.

Sites used:
http://wiki.answers.com/Q/What_is_the_density_of_aluminum
http://en.wikipedia.org/wiki/Oak
http://answers.ask.com/Business/Constructions_and_Materials/what_is_the_density_of_glass