57 We are starting constant acceleration particle model (CAPM) in the conceptual classes, and this is the first time I’m doing CAPM with students who know the difference between balanced forces and unbalanced forces. Another first is doing the paradigm lab using video analysis, so we started with each group making a video to analyze with a different number of bricks creating the slope. I use the apparatus I learned to make from Rex Rice when I took the Modeling Instruction workshop in 1997. It’s a disk made of particle board with a couple of golf tees for an axle. It rolls surprisingly slowly down a ramp made of two pieces of conduit, held at constant separation by two pieces of 1×2 with equidistant holes drilled in it. In the past I’ve had students mark the conduit with dry-erase markers and use stopwatches for timing. I’m hoping for better data this year, as well as teaching the students to use video analysis.