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### Falconphysics Democast

 This is my page of show notes for Falconphysics Democast (iTunes Link). A series of videos I'm creating for the MI Learning section of iTunesU. These videos are of higher quality and show a greater attention to detail than the other videos I've created.

#### Images in Plane Mirrors

posted Nov 8, 2009, 5:37 AM by Steve Dickie   [ updated Nov 8, 2009, 5:50 AM ]

 How much bigger than me does a mirror need to be so that I can see my whole body?What do we do?Illustrate both with and actual mirror and ray tracing the minimum length of mirror that I need to see my whole body.Show that image distance equals object distance for plane mirrorsDemonstrate how two way mirrors work.Credits:I got the full length mirror demo from Dr. Peter Hopkinson (he presented it at the 2009 summer meeting of the AAPT)Thanks to Al Gibson and the DMAPT for the two way mirror filmEpisode available at iTunesU - Falconphysics Democast Images in Plane Mirrors (iTunes Link)

#### Inertia

posted Nov 8, 2009, 5:30 AM by Steve Dickie   [ updated Nov 8, 2009, 5:44 AM ]

 Newton's First Law: What is it? What does it mean? What are its implications? What keeps objects "going"?Synopsis:What keeps a thrown object moving forward?What is inertia?A couple of simple demos are done to illustrate inertia.Episode available at iTunesU - Falconphysics Democast Inertia (iTunes Link)

#### Joe Jump

posted Nov 8, 2009, 5:27 AM by Steve Dickie   [ updated Nov 8, 2009, 5:44 AM ]

 In this session we investigate the motion of a "Throwing Up" problem. We focus on the motion of an object while it's in the air.Key take away points:Acceleration is downward on the way up and on the way downVelocity is zero of an instant at the topYou can have zero velocity and still be acceleratingEpisode available at iTunesU - Falconphysics Democast Joe Jump (iTunes Link)

#### Superman Jump

posted Nov 8, 2009, 5:22 AM by Steve Dickie   [ updated Nov 8, 2009, 5:44 AM ]

 How fast would Superman leave the ground when he Leaps a Tall Building in a Single Bound? This one was inspired by James Kakalios' Physics of Super Heroes. I also used it as a way to illustrate how to solve kinematic problems without using the traditional kinematic equations.Remember:Area under a velocity-time graph is displacementArea under an acceleration graph is change in velocityUsing both of these relationships it is possible to derive the needed equations.Episode available at iTunesU - Falconphysics Democast Superman Jump (iTunes Link)

#### Movie Production 1 - Microphones

posted Nov 8, 2009, 5:18 AM by Steve Dickie

 I was asked to show how I create my videos. Here's the first one. It deals with microphones. Audio is the most often neglected part of amateur video production, but really is one of the most important parts.Don't rely on the microphone in your cameraRecord audio directly to your computerNarrate video after it's in your movie software of choiceUSB microphones are better than ones that plug directly into the microphone portMy Guitar Hero microphone is great. You may already have one so this would be a free option.Episode available at iTunesU - Movie Production 1 - Microphones (iTunes Link)

#### Lasarium

posted Nov 8, 2009, 5:13 AM by Steve Dickie   [ updated Nov 8, 2009, 5:46 AM ]

 Learn how to Build a cool Laser Light Show that can be used to show sound is about vibrations in matter.Materials:Small piece of mirrorHollow cylinder with no endsBalloonRubber cement (or something else to affix the mirror to the balloon)LaserSpeakerCredits:High Speed videos were created by meThanks to Don Pata and the DMAPT for the Lasarium supplies and idea.Episode available at iTunesU - Lasarium (iTunes Link)

#### Build a Sound

posted Sep 29, 2009, 9:43 AM by Steve Dickie   [ updated Sep 29, 2009, 9:47 AM ]

 Almost all sounds we hear are composed of multiple frequencies interfering with one anotherUse Audacity to analyze a sound for its component harmonicsUse the Generate Tone function to reproduce the component frequenciesAudacity is free and is available for Windows, OS X, and Linux Episode available at iTunesU - Build a Sound (iTunes Link)

#### Interference and Standing Waves

posted Sep 20, 2009, 5:25 AM by Steve Dickie

## Interference

• Two waves or pulses in the same place at the same time combine and appear to be a single wave or pulse. The waves continue on unchanged by the interaction in the direction of propagation (i.e. the direction they were traveling).
• Constructive interference happens when the resulting amplitude is larger.
• Destructive interference happens when the resulting amplitude is smaller. In some cases there is Complete Destructive interference where there is no sign of a wave or pulse passing.

## Standing Waves

• Waves interfering with their own reflection in such a way as to appear to be standing still.
• Resonance happens when standing waves form. Small amounts of force applied at the right frequency result in larger and larger vibrations.
• Area of minimum vibration are called nodes. Between the nodes are areas of maximum vibration that are called antinodes.
Episode Available from iTunesU - Interference and Standing Waves

#### Longitudinal Waves

posted Sep 20, 2009, 5:21 AM by Steve Dickie   [ updated Sep 20, 2009, 5:26 AM ]

 Particles vibrate parallel to the direction energy is transferredCompression - Particles closer togetherRarefaction - Particles more spread outSpeed of the wave depends on the medium and not on the amplitudeLinksSimulation - Wave Interference at PhETEpisode available from iTunesU - Longitudinal Waves

#### Transverse Waves

posted Sep 20, 2009, 5:17 AM by Steve Dickie

 Particles move perpendicular to the direction of energy transferCrest - Top of the WaveTrough - Bottom of the waveWavelength - Measure from one point on one wave to the same point on the next waveAmplitude - Height of a wave measured from rest positionSpeed depends on the mediumEnergy is proportional to the square of the amplitudeLinks:Simulation -Wave on a String from PhETEpisode available at iTunesU - Transverse Waves

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