Demonstrations tomorrow: pendulum and quantum physics

Tomorrow (Thursday) we will have a demonstration and measurements of the periodic behavior of pendula. Amanda and Rylee will be taking digital video, too, for iTunes U and YouTube.

We will also map out the momentum of the pendulum and build a foundation for the quantum physics on our agenda for the last three weeks of the semester.

Today's demonstration

We did a falling five dollar bill demonstration in lecture today, from which we began a discussion of motion, velocity and acceleration.



Thanks, Manny, for being a good sport and helping us out as a volunteer.

Also, the digital video versions are uploaded into iTunes U.

Helium

Now the helium spectrum. Both sections need to be familiar with this.



Higher definition versions are in iTunes U.

Hair on end

Tomorrow and Thursday, we will demonstrate the concept of voltage with the van de Graaff generator, so famous for making your hair stand on end. If you want to try it out, make sure to wash your hair but no styling gel or other goop. My hair is too curly (a sign of geniusness), but even for straight hair, you never know whose hair will do the best.

This photo of Ashlea from a few semesters ago, is one of my favorites.

Force on current carrying copper bar

This video will be available soon.

What direction is the horseshoe magnet's magnetic field in this demonstration. The camera is sharp enough that you can figure it out after close inspection. Good camera work, Michelle P.!



Large nice versions are already up on iTunes U.

Faraday cage 2

Here is the Faraday cage video from afternoon section, complete with front row guidance from John H.



And the big nice versions, in .m4v format, are in our iTunes U in the "Demonstrations" tab and in the "Demonstrations-mobile" tab.

Remember: we will feature Faraday cage questions on the final exam, so give this demonstration and the earlier video a good look.

By the way, in each of the Faraday cage videos, we discuss the graphite in the pencil. Here are some links to Webelements.com, for carbon and, for comparison, copper. Look at the resistivity of each substance. It is the intrinsic measure of a substance that gives you an idea how well it conducts electricity: low resistivity, good conductor.

1. Carbon spec sheet.
2. Copper spec sheet.

Lydia and the van de Graaff generator

Sweet video from the afternoon section yesterday.