Rube Goldberg - A very nice Rube Goldberg apparatus designed by two of my Physics II students to make a cup of lemonade.

Ball Drop - Balls are dropped in front of a grid projected with an overhead onto a screen. The horizontal lines of the grid are 2 cm apart as measured on the screen. Use the arrow keys to advance the movie frame by frame. There are 29.97 frames per second (0.03337 seconds between successive frames). Verify g = 9.8 m/s/s.

• Ball A - A golf ball is dropped. Can also calculate the energy lost when the ball hits the floor and bounces back up.
• Ball B - A solid steel ball 3.6 cm in diameter is dropped.
• Ball C - A solid steel ball 2.4 cm in diameter is dropped.

Elevator Barbie - What would people experience inside a freely falling elevator? Would they hit the ceiling? A barbie is placed inside a large plastic "elevator" with an open top. Use the arrow keys to advance the movie frame by frame and observe what happens to Barbie.

2-D Collisions - Two plastic pucks are collided on an air hockey table. One puck is stationary.

• A - Equal mass pucks. See how the angle between the pucks after the collision is always 90 deg.
• B -Stationary puck is lighter than the heavier puck. See how the angle between the pucks after the collision is always less than 90 deg.
• C- Stationary puck is heavier than the lighter puck. See how the angle between the pucks after the collision is always greater than 90 deg.

Wave Demos

• Longitudinal Waves - Notice the direction of the displacement for a longitudinal wave pulse in a brass spring and a slinky.
• High Frequency & Low Frequency - Two transverse wave pulses are sent down a long brass spring. See the relationship between wavelength and frequency.
• High Amplitude Brass - Low Amplitude Brass - High Amplitude Slinky - Low Amplitude Slinky - Compare the speed of a transverse wave pulse in a long brass spring and a slinky. See if the amplitude of the pulse affects its speed. (The dark lines on the paper grid are 10 cm apart; the smaller lines inside the dark lines are 2 cm apart. Use the arrow keys to advance the movie frame by frame. There are 29.97 frames per second (0.03337 seconds between successive frames).
• Superposition of Waves: Constructive Interference & Destructive Interference 1 & Destructive Interference 2 - Two transverse wave pulses are superimposed over a paper grid. The dark lines on the grid are 10 cm apart, and the smaller lines inside the dark lines are 2 cm apart. Use the arrow keys to advance the movie frame by frame. Compare the amplitude of the individual wave pulses to the amplitude resulting when the pulses superimpose.
• Reflection off a Stationary Boundary - See how a transverse wave pulse reflects off a stationary boundary.
• Reflection off a Moving Boundary
  • Brass to Slinky - A transverse wave pulse is sent down a brass spring connected to a slinky. See the directions of the resulting wave in the slinky and the reflected wave in the brass spring. Use the arrow keys to advance the movie frame by frame.
  • Slinky to Brass - A transverse wave pulse is sent down a slinky connected to a brass spring. See the directions of the resulting wave in the brass spring and the reflected wave in the slinky. Use the arrow keys to advance the movie frame by frame.
• Standing Waves - See my students easily generate the first, second, and third harmonics for a standing wave in a brass spring. Count the nodes and antinodes. See the students struggle to produce higher harmonics and the subsequent noisy interference.
• Flame Tube - Fiery demo of a standing sound wave in a stove pipe charged with natural gas. Be sure to turn up the sound on your computer's speakers.
• Soap Bubble - A sound wave is generated below a soap bubble. See the effects on the soap bubble. Be sure to turn up the sound on your computer's speakers.

Wave Animations by Dr. Russell of Kettering University

• Types of Waves - Particle-level computer animations of transverse, longitudinal, and surface waves.
• Superposition of Waves - interference, standing waves, beats
• Doppler Effect - animations of vsource = 0, vsource < vsound, vsource = vsound, vsource > vsound
• Mach 1 video - .MPG video of F-18 breaking the sound barrier; don't know the orginial source to credit for this

Circular Motion A & B & C - A 16.2 g rubber stopper is twirled in a 50 cm radius circle. Use the arrow keys to advance the movie frame by frame. There are 29.97 frames per second (0.03337 seconds between successive frames). Notice the direction of my hand to keep the ball moving in a circle. Notice the direction of the rubber stopper's velocity when I let go of the string. Also possible to determine period, speed, centripetal acceleration, and tension in the string (centripetal force). Only difference between each video clip is the release point when I let go of the string.

Electric Field Animations - University of Florida

Parabolic Motion - A tennis ball is tossed back and forth in front of a grid projected with an overhead onto a screen. The horizontal lines of the grid are 2 cm apart as measured on the screen. Use the arrow keys to advance the movie frame by frame. There are 29.97 frames per second (0.03337 seconds between successive frames). See that the horizontal component of the ball's speed stays relatively constant while the vertical component accelerates by g = 9.8 m/s/s.

Pendulum Cart - A pendulum swings back and forth on top of a dynamics cart on a track. Use to demonstrate center of mass and conservation of momentum.

• Pendulum Cart 1 - The center of mass stays relatively still since the pendulum and cart are released simultaneously.
• Pendulum Cart 2 - The cart periodically jumps to the right since the cart is not released until the pendulum reaches the other side.

Inertia demo

• Yardstick - A yardstick hanging over the edge of a table has 100 g of paper on top of the table-side. A hard karate chop breaks the yardstick in half with the help of inertia.
• Tablecloth - the classic "pull the table cloth out from under the dishes" demo

Inertia & frame of reference demos (use the arrow keys to advance the movie frame by frame)

• Dynamics Cart 1 - Is the cart moving or is the track moving?
• Dynamics Cart 2 - Same as above except with a toy observer next to the track.