Cell phones are great for science - I would suggest you download and install the following 2 free apps (see images above/previous screen)

1. Hz Frequency Sound Generator (LuxDeLux)

2. Soundcorset tuner & Metronome

The new standard on sound and vibration is interesting in that it goes in both directions - that sound can cause a vibration and that vibrations create sound.

What is sound? Sound is a compression wave caused when a vibrating object pushes the particles of a substance (a medium ... that through which a wave travels) together and then they bounce back to normal spacing.

For this station, you need access to an instrument. Guitars (and other stringed instruments) work great. Pianos are o.k. - the announcements for this class going back to March indicate how you can access a piano on campus (rooms in the Center for the Arts) are open during regular business hours.

With the guitar or piano, you can see some differences in the strings. There are 2 differences which should be obvious between the six strings on a guitar, and 3 on a piano. (In science, we call things that can be different or can be changed variables).

Make a table (call this table 1).. Write down the variables that are immediately obvious.

What are the different values that each variable can take (in other words, the variable "position" in basketball might have 5 values - point guard, shooting guard, small forward, power forward, and center)? What are the values that this variable can take on the instrument?

How do these variables and values influence the pitch (high or low) of the guitar or piano? Play notes on each string and record the sound (if using the tuner app, the frequency will display in small numbers if you click "tuner" and then play a note). Add this information into your table.

Now, the same thing can happen with other objects. We use this idea in music, in that most instruments will have a container of air (the body of a piano, drum, guitar, violin, or the tube of wind and brass instruments) and when a sound is produced by a vibrating reed, string, etc. it causes the air inside that container to vibrate at the same frequency, amplifying the sound (what happens if there is no container of air? Ever heard an electric guitar that was not plugged into an amp - no resonance chamber, almost no sound?)

O.K. Generate a sound (that frequency sound generator app). Although the sound might be kind of quiet at low frequency, you can change the shape of the wave to a square or triangle or sawtooth wave and that will make it louder.

Now hold it close to, and then touch it to, a variety of materials. Those that surround a hollow of air (balloons, cups, glasses, decorative boxes to put around the tissue box, empy serial boxes, garbage cans, etc.) should work well (the hollow wooden body of a musical instrument works even better). Hold it close to, put it inside, and touch the speaker to each. Adjust the frequency of the wave FOR EACH OBJECT from low frequency to high.

Final note - you might need to remove your case from your cell phone for best results.

1. Does the object itself start to vibrate from the sound? Do some vibrate more than others? Does frequency matter? Is there a particular pitch that really makes something vibrate? If so, you found its natural frequency (maybe).

2. Does the sound get louder? Again, does frequency matter (i.e. some objects make low pitch noises louder, some make high pitch noises louder ... this is why the size of the cones for woofers and tweeters are different in your car speakers. What patterns do you find?