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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 mirrors
  • Demonstrate 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 film
Episode 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 down
  • Velocity is zero of an instant at the top
  • You can have zero velocity and still be accelerating
Episode 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 displacement
  • Area under an acceleration graph is change in velocity
  • Using 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 camera
  • Record audio directly to your computer
  • Narrate video after it's in your movie software of choice
  • USB microphones are better than ones that plug directly into the microphone port
  • My 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 mirror
  • Hollow cylinder with no ends
  • Balloon
  • Rubber cement (or something else to affix the mirror to the balloon)
  • Laser
  • Speaker
Credits:
  • High Speed videos were created by me
  • Thanks 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 another
  • Use Audacity to analyze a sound for its component harmonics
  • Use the Generate Tone function to reproduce the component frequencies
  • Audacity 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.
Links
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 transferred
  • Compression - Particles closer together
  • Rarefaction - Particles more spread out
  • Speed of the wave depends on the medium and not on the amplitude
Links
Episode 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 transfer
  • Crest - Top of the Wave
  • Trough - Bottom of the wave
  • Wavelength - Measure from one point on one wave to the same point on the next wave
  • Amplitude - Height of a wave measured from rest position
  • Speed depends on the medium
  • Energy is proportional to the square of the amplitude
Links:

Episode available at iTunesU - Transverse Waves

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