# Day 87: In Physics, Circuits Break You

Tuesday, Feb 6

Physics: Turning in the polarizing light lab. I just checked over the final and there’s one part of one question on polarized light. I’m also going to rewrite that question to make it approachable in more than one way, because some kids understand the concept through words and others through diagrams, so I’ll give them options. The rest of the period was them working on their presentations for tomorrow and Thursday. I’m kind of excited to see how they help their peers learn about color.

Honors Physics: Continuing electrostatics with forces. They were amazed that we were actually doing problems from the textbook again. Well, yeah. You want to go back to lectures, we’re going to go back to doing practice problems to apply the knowledge you are supposed to learn during a lecture. Tomorrow will be superposition of forces before starting field stuff. My goal is to have them building circuits by next Tuesday when we have our next double period.

AP Physics: We did a few more circuit clicker questions and then moved on to capacitors. They’re finally starting to internalize that capacitance depends on the physical properties of the capacitor and not the charge or the potential difference. It’s taken many many questions of that sort to get it through to them. It’s a very typical response to seeing any kind of equation showing direct proportionality with a constant if they don’t recognize what is constant and why. The same thing happens with the wave equation. We also did baby’s first Kirchhoff’s Law problem to show how intuition doesn’t work for circuits more complicated than basic combinations of series and parallel. I looked at it, listened to a student’s intuitive explanation, and said I couldn’t confirm or deny it without the math, so we went through the math and it blew all our minds. Physics, I tell you what.

I spent a large part of study time working with a student who needed help writing a paper. It was basically a list of physics non sequiturs that were technically true but did not show any depth of understanding. Below is the photo he took to illustrate diffraction, which I’m including because I think it’s pretty. Next Thursday the regular physics class has a photo contest project due, so I’ll try to get those posted on here so you can see the levels of both effort and total non effort that ensue.