Tracker for Video Analysis

I've blogged about Tracker before, but I have to say yet again that it totally rocks. I have this video clip that I use with my students every year of a student jumping as high as he can. Joe, the student, does the predictable, he lifts his legs and arms while in the air.

Traditionally I've had students track the motion of three points on Joe. His head, torso, and feet. We've already talked about the acceleration due to gravity near Earth's surface so I ask them why the acceleration of the different body parts is not -9.8 m/s/s. I also make them explain why Joe's torso is closest to -9.8.

Well Tracker allows us to do one better. We can track all of Joe's body parts and then Tracker will plot the center of mass for us. I used a table (from Oregon State) that I originally saw on the Dot Physics Blog for the distribution of mass in bodies. I ended up finding the acceleration of Joe while in the air to be -9.824 m/s/s (about 0.18% error).

Tracker is free and works on Windows, OS X, and Linux.

Podcasting on iTunesU

I applied and was invited to submit podcasts to the MI-Learning section of iTunesU. My main focus will be demos I use with my physics students. This way if they miss class when I do a demo they don't have to miss it completely.

Additionally I want to make sure my videos can be used by other educators who might not have all the right equipment to do demos or who might not know how to do them. I will be doing some videos intended to teach other teachers how to do various demos in class. Such as the Lasarium shown below.

You can find all of my Democasts at iTunesU, at Blip.tv, or the Archive.org.