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

Questions to ponder:

• What is music?

• How would you define it in physical terms?

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

Oscillations/Simple Harmonic Motion

Period

time

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 = ?

Damped Oscillations

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

What’s all this got to do with music?!

•Answer: Everything

Lab Reports• Introduction: what you are studying and why

• Methods: what you did and how it works-- theory and techniques described in detail

• Results: what you observed

• Discussion: what it all means