Density sound Lab

Sophie Moynihan

7B

Science lab

Guiding question: How does the density of an object affect the properties of sound traveling from a tuning fork.

Hypothesis: I predict that the denser an object the louder the sound will be

Materials: Tuning fork (256 C)

Box

Desk

Wall

Locker

White board

Procedure: We are testing materials of different densities to see which will make the greatest or most intense sound

Box
Density= 0.65 g/cm3
Low and really buzzy. Not a very projectile sound, pretty quiet

Desk
Density= 0.65 g/cm3

Low, quiet sound. Not a lot of vibrations and not a very loud sound

Wall
Density= 1.1 g/cm3
Vibrations but no sound (to dense??) pretty much stopped the tuning fork from vibrating

Locker
Density= 7.859 g/cm3
High twang sound, one long continuous sound. Super loud, can be heard from several lockers down

White board
Density= 2.7 g/cm3
Higher then wood box, buzzy. Super projectile and can be heard even if you aren’t pressing your head to the whiteboard.

Record and analyze: After testing all of our objects, these were the results we got a variety of results. Most of them really contradicted our hypothesis, but we got some really valid data and also learned some things about how the materials effect how the sound will travel and bounce because of what they are made of.

Conclusion: Does the density of an object effect the waves traveling through it? We hypothesized that a denser object would make a louder and sharper sound. After many long tests, we can conclude that the denser an object, the lower and more faint and deep the sound it makes will be, and the less dense an object, it will make a higher and more shrill sound. My hypothesis was completely off, and in a way the results we got make much more sense. If an object is less dense, it will be easier for the sound to travel as appose to if it is denser. You can think of it as if you were trying to hear someone from the other side of a wall. It is easier to hear someone if the wall is made of some kind of flimsy wood and foundations as oppose to if it were concrete.

Further Inquiry: There are a lot of components that probably would have messed up some of our research if it were a touchier experiment. For one, we hit the tuning fork with a different aggression every time, which gave us a variety of different sounds. Also, about half way through the experiment, we realized that temperature was a huge component in the way sound travels. We had been testing the railing outside, which was at least 20 degrees colder, so we decided to measure sound in the lockers instead. A last thing that probably changed the result of our tests is that we were putting our heads at different positions every time, therefore making the sound travel a different distance every time. Other than that and a few other slip ups, the experiment went smoothly and I feel like it was one of the most productive experiments we have ever done.
Sites used
http://www.wolframalpha.com/