# Day 22: Bullseye! and other stuff I guess

Thursday, Sept 28

I’m so far behind in grading it’s hilarious and sad. So sad. Somehow Physics Honors makes 10x the papers for grading as the other classes. I don’t know what I’m doing right or wrong or what with each class. I’ve got to find a better balance and better organization for what papers have been graded, which are corrections, and which are to be handed back.

Physics: Going over the homework took so long I had no time to do anything else, but there were some good discussions and thinking happening. We practiced some more system schema, which showed me yet more profound weaknesses in the Hewitt book. The students couldn’t even identify objects whose motion we care about in a system and continued to be confused about how forces work, and that’s at the end of the unit on Newton’s second and third laws. This book has so many problems.

Honors Physics: Continued practicing goal-less problems using CVPM/BFPM and CAPM/UBFPM. The students were really starting to get it and see how all the models were complementary and helped to convey information one to another that you needed multiple representations to fully understand.

AP Physics: Bullseye lab! We started with a goal-less question quiz about a block sliding down a ramp with friction. I haven’t graded it yet. Honestly not entirely sure how to grade it, and I missed the PLC last night so I couldn’t ask. I’ll figure something out.

Anyway, the lab was a bullseye lab. I found an ancient projectile launcher that shoots 1″ projectiles. First I set them to discovering the muzzle velocity of the launcher. It was hilariously inconsistent. Then after they did the calculations, every single trial went 5-10cm short of what they calculated. These kids are super good at the calculating things, and everyone did their calculations flawlessly, but the launcher was a jerk and most of them didn’t even hit the paper. It’s also possible they messed up their measurements, sure, but I’m pretty sure it was the laughable inconsistency of the launcher coupled with the projectiles themselves being a fairly light plastic rather that steel. One group did try to figure out air resistance but it got too complex and was taking too long, so they gave up. Added to my “new equipment” list is “a launcher that doesn’t suck”.