Today was our third class of Physics 9, and our first day of whiteboarding. They had spent some time working on their first qualitative LOL diagrams, so now they were ready to discuss some of the trickier points together.
I let them sign up for problems and we talked about making good mistakes. A few groups checked their mistakes with me, and they were overall really thoughtful about that process.

The discussion was excellent. They brought up every point I could have wanted with almost no input from me at all. So amazing for a first day of whiteboarding.

The highlight was the final problem. One student insisted that if the person pushing a car were inside the system (instead of outside doing work on the system), they would be storing energy as spring interaction energy. The other students were pretty convinced that humans weren’t good springs, and we got into a discussion about how else the energy might be stored. We invented our fifth flavor (chemical interaction energy) because they said that to push a car, the person needed to eat their spinach.

On their way out, one kid asked, “What’s the most delicious flavor of energy?” Obviously it’s Uchem, right? The one that comes in ice cream?
Final treat—some close-ups on the illustrations on the big board.