Guiding Question:

How does density of various solids affect the way the sound waves travel from the tuning fork?

Hypothesis:

I believe that the denser the material is the longer it will take to travel for you to hear, making the sound softer and much shorter.

Materials:

· A 426.6 A tuning fork

· A 256 C tuning fork

· A whiteboard

· A locker

· A desk

· A cement wall

· A notebook

Procedure:

1. First you must take your two tuning forks.

2. Find the first material you will be observing.

3. Tap the 426.6 A tuning fork onto the material and the press the round, flat end against it.

4. Listen closely to the sound.

5. Observe what you hear.

6. Do this with all the other materials.

7. Repeat steps 2-6 but with the 256 C tuning fork.

Material	Density	Loudness with 426.6 A tuning fork	Length with 426.6 A tuning fork	Loudness with 256 C tuning fork	Length with 256 C tuning fork
Locker	7.85 g/cm3	Really loud and very sharp, it hurts your ears	Lasts for about 30 seconds.	Not as loud as the other fork, doesn’t hurt your ears.	Lasts for about 24 seconds
Whiteboard	2.8 g/cm3	Loud same as locker	Lasts for about 17 seconds.	Also much quieter and lower.	Lasts for about 14 seconds.
Desk	0.75 g/cm3	Much louder and hallow song it is deeper. You can hear it without having to put your ear near the fork	Lasts for 15 seconds	You have to actually put your ear to the fork to hear the sound and listen intently	Lasts for about 11 seconds
Wall	3.12 g/cm3	Quieter than other materials you have to listen closely	Lasts 16 seconds	Much quieter you can almost not hear the sound but you can feel the vibrations.	Lasts 15 seconds

RECORD & ANALYZE: Looking at the data pattern I can see is that the denser the material makes it louder and longer. I can see this because all the dense materials are very loud and the sound is longer. You can see that the locker is very dense and then the sound is loud and quiet. Yet the desk was the least dense out of all the materials so it had the quietest sound and lasted the least.

Conclusion: So does the density of a material affect the length of the sound and the loudness of the sound. From the data that I found I can conclude that the denser a material is the louder and longer the sound is. So if this is true that the less dense a material is the quieter it will be and the shorter it will last. The variable in this project was the material and the tuning fork. We changed these things to test the how density effects the loudness and the length. The prediction I made was actually incorrect because the denser the material the louder and lengthier the sound. Yet I said that the denser the material the softer and shorter the sound will be. This lab taught me more about sound and the way density effects sound. From now on I will understand why when I tap on wood compared to when I tap on a locker the difference.

Further Inquiry: I think the biggest cause of error in my data would probably be that when I was listening to the tuning fork I miscounted the seconds or I might have accidently hit the fork a little harder during one test than another. Maybe next time I could possibly use a timer to count how long the tuning fork rings. Maybe I could have something that would hit the fork exactly on point every time. Next time I think I actually will use a stopwatch to record how long the sound lasts. To further continue this experiment, one area that I could elaborate one would probably be how the length or size of the tuning fork changes the sound. From what I found in the experiment it changes the pitch yet I would like to try this experiment with a wider variety of tuning forks.

Check out the video below to see a tuning forks vibrations and sound:

http://www.youtube.com/watch?v=3m4ztrpmX-s