# Day 37: Still Circling. Thankfully Not the Drain.

Wednesday, Oct 2

Physics: Today I handed back exams and students worked on corrections. Grades were ok. The most common mistake was on a question where there was a hanging mass connected over a pulley to a second mass on a table (half-Atwood). They had to calculate the U of the hanging mass (20 J), then the K of the mass on the table (16 J), and then tell me how much K the hanging mass had just before it hit the ground. Everyone was able to do the first and second with no problems. Not a single student missed those points. Substitute/evaluate is strong with this class. The majority of students said that the hanging mass had 20J of K. The three that gave the correct answer were super on top of things, but even though we did a lab on this exact situation, most of the students were not able to appropriately apply conservation of energy for a two-object system. I work with students individually during this day, and I explained this at least eight times. There were eight lightbulbs that went off after we talked, but I guess I’ll see on the final exam whether or not that lightbulb stays lit.

Honors Physics: Horizontal circular motion. We did a bunch of practice problems. There was a lot of confusion and questions and far too much conversation around when you are “allowed” to substitute in the numbers, so after that I stopped giving any numbers and made them solve everything symbolically. They are capable of it, and I think both finding symbolic answers and then being able to reason with them will be a focus more than getting a number. I don’t know why that second step (the reason with the result) wasn’t more obvious to me, but there it is.

AP Physics: The two classes are much closer to being caught up now. Today the first class did a bunch of example problems of vertical circles and loops, looked at the conical pendulum for the lab tomorrow, and then just barely started horizontal circular motion. The second class finished vertical circles and looked at the conical pendulum, so everyone is ready for the lab tomorrow, and then I’ll have them both working on horizontal circular motion on Friday and BAM everyone’s caught up.