This year I'm only doing my friction lab with my honors class, because quite frankly, the other classes are moving too slowly, and I want to have time to do fun things with light at the end of the year. (I haven't yet had enough time in June to light things on fire with concave mirrors and convex lenses, for example.) So only the honors class got to play with my old shoes.
It went fairly smoothly, although some of them weren't quite sure what the normal force was or how to find the force of friction. They took four data points for each shoe-surface combination, and got data that was reasonably well fit by the straight line theory predicts. I used the SMARTboard mostly as a projection screen for Graphical Analysis, which does a nice job of grpahing all the data in a coherent fashion. We'll go over the lab tomorrow, do a few problems involving solving for or using mu, and then they'll be ready for the circular motion test on Friday.
The other classes did today what the honors class did yesterday: break their brains on the idea of rotating reference frames and simulated gravity. We used the turntable to help them see the rotating reference frame and the inertial reference frame, but most of them just sort of humored me as we went through Hewitt's worksheet. They were largely amazed at the idea that we don't yet have artificial gravity: that the astronauts in the International Space Station spend their days either floating or strapped where they need to be. I wandered over to NASA's ISS site at the end of class and showed them some pictures of astronauts on board. The whole idea of a place without (human-perceptible) gravity blows their minds. It's a pretty cool concept. The girl who asked a week or so ago about how astronauts do laundry was especially thrilled to find out that I've emailed both NASA and the AstronomyCast crew with her question.