This preview shows pages 1–3. Sign up to view the full content.
1
Lecture 38
Review of waves
What is a wave ?
Examples:
Sound waves (air moves back & forth
A wave is a traveling disturbance that
transports energy but not matter.
– Sound waves (air moves back & forth)
– Stadium waves (people move up & down)
– Water waves (water moves up & down)
– Light waves (what moves??)
Waves exist as excitations of a (more or less)
elastic medium.
Amplitude:
The maximum displacement
A
of a point on the wave.
Period:
The time
T
for a point on the wave to undergo one complete
oscillation.
A few parameters
1
f
Frequency:
Number of oscillations
for a point on
the wave in one unit of time
Amplitude
x
y
the wave in one unit of time.
Angular frequency:
radians
ω
for a point on the
wave in one unit of time.
2
Wavelength:
The distance
λ
between identical points on the wave.
Connecting all these simple harmonic motions
k
2
Wave number
k
:
Speed
:
The wave moves one wavelength
in one period
, so its
speed is
v
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document 2
Interference, superposition
Q:
What happens when two waves
“
collide?
”
A:
They ADD together! We say the waves are
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 09/21/2011 for the course PHYS 222 taught by Professor Johnson during the Spring '07 term at Iowa State.
 Spring '07
 Johnson
 Physics, Energy, Light

Click to edit the document details