Tuning Fork Experiment

Problem: How does the length of sound change when a tuning fork is tapped on different surfaces?
Hypothesis:  I think that the hardest surface will have the longest sound because it won't dampen any vibrations which create the sound.
Experimental Design:
• Variables
• Constant variables
• Tuning fork
• Where I hit the tuning fork on the object
• Independent variables
• The objects
• Dependent variables
• How long the tuning fork made sound
• External variables
• How hard I tapped objects
• Procedure
1. Gather materials
2. Get stopwatch ready
3. Test first object (wall) and time
4. Stop stopwatch
5. Record results
6. Get stopwatch ready
7. Test first object again (wall) and time
8. Stop stopwatch
9. Repeat steps 2-8 with the four remaining objects
• Materials
• Tuning fork
• Wall
• Table
• Notebook
• Natalie's Hand
Observations:

Conclusion:
I wanted to see what kind of objects would make longer sounds when a tuning fork is tapped on them.  My hypothesis was that the harder the object, the longer the sound.  Looking at my data, my hypothesis was supported. The harder objects, such as the wall or the table, had longer sounds than the softer ones. 
Once I did more research to find out why harder objects had longer sounds, I found it was because the vibrations weren't dampened as much.  So when the tuning fork was hit on the object the object didn’t absorb any of the sound that the tuning fork would make.  Though when I tapped the fork on my hand or the notebook, more of the vibrations were dampened because it wasn't completely stiff. 
My only external variable was that I couldn't hit the object with the exact same force for each object.  I tried to use about the same force with each object, but it wasn't perfectly accurate.  Overall, I overcame this variable as best as I could.