This preview shows pages 1–3. Sign up to view the full content.
Physics 7C
DLM 02 Overview
DLM 02
Model:
Plane Waves
Act 8.1.3
Representing a 1D Harmonic Wave Graphically
(~90 min)
Learning Goals:
•
Understanding that the displacement of the medium when a harmonic wave is present depends on
two parameters: position and time
•
Understanding that it takes two graphs, one as displacement of medium vs. time and one as
displacement of medium vs. distance to completely represent a wave graphically
•
Understanding that the graph of a harmonic wave as a function of either position or time is
sinusoidal (i.e., corresponds to a sine or cosine function)
•
Understanding that it takes a mathematical function of two variables (e.g., y and t) to represent a
wave (i.e., a wave function)
Act
8.1.4
Waves and the Wave Equation
(~50 min)
Learning Goals:
•
Solidify ideas about wave parameters and graphing waves
•
Understand that
y(x,t)  y
0
=
Asin 2
π
t
T
±
2
π
x
λ
+
φ
⎛
⎝
⎜
⎞
⎠
⎟ =
Asin
Φ
(x,t)
is the 1D harmonic wave
function and that when graphed as a function of either x or t, while holding the other variable
constant, a sine wave results.
•
Begin understanding the total phase
Φ(
x,t)
Reading Assignment
•
Read the first portion of the 7C Course Notes on Waves.
(available online)
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document Physics 7C
Activity
8.1.3
DLM 02
Representing a 1D Harmonic Wave Graphically
View the following Java applets within the Safari web browser on the Apple iBook located at your
table; these files, named “transverse.html” and “longitudinal.html”, are linked to a main file called
“overview.html”, which is found in the folder “Student Files/7C” on the hard drive.
Discuss in your group and put on the board
(
actually do the work at the board
)
:
1) Start the animation for the
Transverse Wave
.
Which way is the wave moving?
2) Click on a point in the animation at least
λ
/4 (a quarter wavelength) away from the edges.
Describe the
motion of the yellow dot that appears (for now we will ignore the red dot).
Click on another spot in the
wave, and describe the motion there.
3) Focusing on the location of the yellow dot, make a graph with clearly labeled axes of the
displacement
of that spot
as a function of
time
.
Make sure you have room to draw another graph directly below it.
The leftmost blue dot is at position = 0 m, the middle at 50m, and the rightmost is at position =
100m.
The time is shown on the screen.
Use these values to estimate numerical labels for your axes.
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 11/15/2010 for the course PHY PHY07C taught by Professor David during the Winter '09 term at UC Davis.
 Winter '09
 DAVID
 Physics

Click to edit the document details