PROBLEM: How can you determine if sound is a physical wave?

PREDICTION:

PROCEDURE:

MATERIALS:  6 jars (same size); water, stick, tuning forks

EXERCISE I.  Stretch a rubber band to different lengths and describe what happens to the pitch of the sound 

EXERCISE II.  Hit the tines of the tuning fork on a hard surface and touch the tines to the items listed below.  Record what happens and see if you can hear the tuning fork.

EXERCISE III.  Using 6 jars, fill each with the appropriate amount of fluid in the chart below.  Record the type of sound produced when you tap it with a drumming stick.  Describe the quality of the pitch.

CONCLUSIONS:  Do the above experiments illustrate that sound is a physical wave?  What else did you learn?