Physics Java on the Web

Waves

BEFORE YOU BEGIN: Highlight the questions you were assigned,
choose FILE, PRINT, SELECTION, PRINT

Wave Characteristics

1. Catch a WavePhysics 2000 - Wave visual - Is this the top or side view of  a wave?________________

2. Frequency and wavelength (This applet takes a while to load)

INSTRUCTIONS  Click on the grey ball and drag it to alter the wavelength and amplitude of the wave.

a. How do you move the ball (on the wave) to alter the wave's wavelength and it's frequency?

b. How do you drag the red ball to increase the amplitudes of the wave? __________

INSTRUCTIONS: 1. Set the wavelength of the wave on the top left to 31 and make its amplitude 1.

Flip the other wave upside down by dragging its ball straight down. Give this wave the exact same
frequency and amplitude as the wave on the left.

c) The wave in the bottom left corner shows what would happen if the two waves you created
would overlap. Draw what you see.

d) What kind of interference does this show. Constructive or destructive? (circle)

3. Transverse and Longitudinal Waves - Phillip Dukes - Brigham Young University

Which wave in this applet shows the way air molecules move when a guitar string is plucked?

Transverse or Longitudinal? (circle)

a) What happens when the wave reflects off the HARD boundary? (scroll down)

b)  Scroll down and look at the wave that is shown crossing over into a new medium. Does all
of the waves energy pass into the new medium? Explain.

c) Which medium is faster, the low density medium or the high density medium? (Circle)

5. Longitudinal Waves, Transverse Waves and Waves of Mixed Type
What is the difference between the motion of the particles in the transverse and longitudinal wave?

Sound

1. Supersonic Planes (Scroll - Applet is found on bottom of page) - Author: Fu-Kwun Hwang

a) Where is the plane when it is finally heard by the ear on the bottom of the page?

INSTRUCTIONS HIT RESET. SELECT A SPEED RATIO OF .5 (half the speed of sound)

b) How much of the plane's travel across the sky can the observer hear the plane?

Wave Behaviors

1. Standing Wave

INSTRUCTIONS  Left Click anywhere on The Applet

a) How many antinodes does this wave have? _______ b) How many nodes does this wave have? _______

2. Standing Wave - Northwestern University

a) What happens when the wave hits the wall on the right to create this standing wave?

# 3. Standing Longitudinal Waves    - Walter Fendt, June 8, 1998

INSTRUCTIONS: 1. Choose "Both sides closed" 2. Raise the frequency to 515 Hz

a) How many nodes do you have? _________

b) How are the particles at the nodes different than the particles in the antinode region?

4. Standing wave and frequency - C. K. Eng - Hong Kong

INSTRUCTIONS: 1. Select "Show Ruler"

a) Increase the frequency. At what frequency do you produce 3 nodes in the string?

b) At what frequency do you produce 4 nodes in the string? What is the wavelength of this wave?

c) 5 nodes?

Doppler Effect

1. Doppler Effect and Sonic Boom - (Soundry)

a) When the plane moves the frequency of its sound wave is changed. How does the frequency of
the planes wave changed on the right hand side of the plane?

b) ... how is the frequency changed on the left side of the plane?

c) Describe how the frequency the observer hears as plane approaches is different than when the
plane departs.

d) Check out the planes motion at higher speeds. Describe what happens when the plane travels
faster
than the speed of sound (Mach 1.5 and Mach 2)

2 The Doppler Effect  II - Colorado University

Which way would the car have to move so that people on the left side of this street scene would
hear a higher frequency than the people on the right side of this street scene?

Wave Interference

a) Which color produced the greatest distance between the central maxima and the first order
bright line?

b) What happens to the distance between the central maxima and the first order bright line
when you:

•     increase the slit distance (d)  ______________
•     increase the distance between the slits and the screen ? (L)_______________

2. Classic Two-Slit Experiment - Colorado University

INSTRUCTIONS:  Turn the light cannon on.  (green button)

a) Slowly decrease the slit separation. What happens the distance between the central
maximum (middle band of light) and the first order bright lines (band of light on either
side of the central maximum)?

3. Polarizing Lenses - Colorado University

Turn any one of the polarized filters until the light on the way to the camera is blocked.
What angle do you have to turn the filters so that the light is blocked?

4 Polarizers

INSTRUCTIONS: Select 2 from the polarizer menu on the left. Move 2nd filter until
all the light is blocked.

What angle on the 2nd filter blocked ALL the light?

Check this one out:  Superposition Principle of Waves

The Electromagnetic Spectrum

1. Vibrating Charges and Electromagnetic Waves  - Physics 2000

INSTRUCTIONS:  Pull the charge on the right down with your mouse arrow.

a) How does increasing the spring tension alter the wave?

3. Spectrum

Click on different parts of the scale shown to reveal which wave is associated with
each wavelength/frequency.

a) Do the dangerous waves tend to have bigger or smaller wavelengths?___________

... bigger or smaller frequencies? __________________

b) What is the mathematical relationship between frequency and wavelength?

_______________________________________________________________________

Fluoroscope (X-Rays) In which part of your hands are the smallest bones found?

Light

Refraction

INSTRUCTIONS: Set the top medium's index of refraction to 1.5 and the 2nd mediums to 1.

#### 1. Snell's Law

a.  Grab the incoming ray and alter the angle until you get an angle incidence that produces
no refraction. What is the smallest angle that produces no refraction ?_______

b. Set the top medium's index of refraction to 1.99 and the 2nd mediums to 1.0. What is the
smallest angle of incidence that will produce total internal reflection.

____________

• Snell's Law:   n1 sin(theta1) = n2 sin(theta2)   Check it out

2.  Refraction

a) Which indices of refraction produce total internal reflection?

b) Set the index of refraction to 1.2. Drag the corners of the rectangle and try to create
total internal reflection. Were you able to do this?

a) Reflection, refraction and diffraction. Which of theses three brings about a change in the
wavelength of the wave?

4. Lasers, frequency, and  wavelength

a) How are the following pairs of light the same and how are they different?

Light from a light bulb and sun light - sketch each below

Monochromatic light and laser light  - sketch each below

•  How are they similar?

• How are they different?

Angles, Reflection and Refraction - Check it out! - Author Fu-Kwun Hwang, Dept. of physics, National Taiwan Normal University

Refraction (Angle, Index of refraction) - Molecular Expressions  - FSU