**AP Physics: Angular Momentum**

Students took a quiz on conservation of momentum, then we finished yesterday’s discussion to introduce the idea of angular momentum. I showed them a Direct Measurement Video of two people on carts pushing off each other, followed by one of a rotating iPod to get a clear analogy for conservation of angular momentum. I think this would be worth taking the time to make a more student-centered discussion with students whiteboarding explanations next time around.

**Physical Science: Motion Graphs**

Students used Vernier Video Physics to do some simple video analysis of a mini hover disk and start looking at position vs. time and velocity vs. time graphs. I had them stay in Video Physics to view the graphs, but students are struggling to make sense of their graphs for constant velocity with the auto scale. I’m debating how I want to change it for next year. I’m leaning towards spending 1-2 days doing constant velocity with a low-tech, breadcrumb approach. I’d probably have students calculate the speed over each interval to make a velocity vs. time graph. Then, we can switch over to video analysis for constant acceleration.