Welcome to PHYS/MUS 102, Spring 2015
Today’s Schedule
9-10:15(ish)Syllabus + Intro StuffLecture: Simple Harmonic Motion
10:15(ish) – 10:30Quick stretch/restroom break.
10:30-11:00Intro to Lab Equip (meet in Howe 204).
11am-2 pmDo experiment (take lunch whenever you wish)
2-3 pmHelp with lab reports (optional)
Introductions• Name • Hometown• Major and class year• Music background• What’s on your playlist at the moment• One fun/random fact
Quotable Quotes
Life without playing music is inconceivable for me.
-Albert Einstein
Image credit: http://www.stumbleupon.com/stumbler/MamaJS/reviews/
Quotable Quotes
To stop the flow of music would be like the stopping of time itself, incredible and inconceivable.
-Aaron Copland
Sound waves/vibrations
Harmonic Analysis
It’s all in your head (?)
One big happy family of musicians and instruments
Three Ants on a String
Three ants (red dots) stand on a guitar string, which is plucked at the midpoint. The string is tuned to vibrate at 200 Hz (a sharp G3). Plot the transverse displacement vs. time for each ant.
Time (ms)Hei
ght
(m)
2 4 6 8 10
Simple Harmonic Motion: Basic DefinitionsA = amplitudeT = periodf = 1/T = frequencyx(t) = displacement/position as a function of time
x(t)
Diving Board Oscillations
Analogy of diving board in musical setting = ?
Transient Decay
Musical note “dies out” Zoomed in (17 msec)
t
Decay time: where amplitude of signal drops to e-1of the max amplitude = ~37% of max amplitude