4/7/09
Post date: Apr 07, 2009 1:26:7 AM
Bell Ringer: Why does the laser bounce around when we reflect it off a speaker that is playing?
Sound waves
Vibrations in the air
Caused by vibrating object (string, drum head, speaker, etc.)
Laser speaker demo
The wave shape represents pressure, or density
Changes in pressure seen with spinning sound tubes sucking up bits of paper (also can be used to demonstrate Doppler effect)
Changes in pressure - flame tube
Sound created depends on a variety of factors with instruments
What material
How vibration is made
Playing technique
Example - banjo
Example - Blue Man Group DVD
Waves Review
Due tomorrow before test
Very similar to test questions