Procedure:
Have 2 partners hold each end of rubbber band and pull until the rubber band is tight.
pull the rubber band about 1 cm away from the middle. Let go. How far does the band move? It vibrates.
reapeat step 2 four times. each time, pull the band back further. Describe how the sound changes each time in the chart below.
Experiment: Frequency:
Have 2 partners each hold one end of the thicker rubber band and pull until the rubber band is tight.
pull the rubber band about 2cm away from the middle. Let it go. Observe the sound
repeat steps 1-2 with the thin rubber band and describe the difference in the chart below.
now, take the thicker rubber band again. Repeat steps 1-2.
Now pull the thicker rubber band again. Observe how the sound changes.
Last experiment:
Have 2 partners hole the thick rubber band just like in step 1.
Now, have one of your partners move his or her hand so that the rubber band is a little bit shorter.
Repeat step 8 two more times, making the rubber band a little shorter each time. Record your observations of the change in sound.
Results:
Experiment 1:
| Distance away from middle | Description of sound |
| 1cm | Low sounding |
| 2cm | Getting slightly higher |
| 3cm | Getting harder to pull |
| 4cm | Higher and can hear vibration |
| 5cm | Highest sounding and tangy sounding |
| Thickness of Rubber Band | Description of Sound |
| Thick | Deep and stiff sounding |
| Thin | Sound a lot higher and sounds slightly twangy |
| Tightness of Rubber Band | Description of Sound |
| Loose | Very low sounding |
| Tight | Medium sounding (slightly higher) |
| Tightest | A lot higher |
| Length of Rubber Band | Description of Sound |
| Longest | Low and stiff sounding |
| Long | High and twangy (can hear slight vibration) |
| Shortest | High sounding and can hear vibration clearly |
Conclusion:
How did the sound change when you changed the amplitude (how far the rubber band was away from the middle point?)
It was harder to pull the rubber band back and it sounded stiffer, it was also easier to hear the vibration of the rubber band.
What happened when you changed the thickness, length, and tightness of the rubber band?
The longer the rubber band the lower and stiffer it would sound. The tighter the rubber band string was the higher the pitch would be, and the thicker the deeper sounding the rubber band was.
Sally is playing the guitar and notices that one of her strings is flat (pitch is too low.) What can she do to fix this?
She can turn the guitar by TIGHTENING the strings (using the knobs on the guitar.)
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