# Day 102: Getting Charged Up

Wednesday, March 14

Happy Pi Day!

Physics: Ray diagrams! I gave them the basic idea and did a few examples, and then they worked on practicing for a variety of different object lengths. I think them working on those together in small groups where everyone had to complete the diagrams was better than them watching me do a dozen different ray diagrams. They asked good questions and seemed to have a pretty solid grasp of the three principle rays and how to trace back when needed. I dig it.

Honors Physics: More circuits! Today we started learning how to use a multimeter to measure current and voltage. They built more circuits and took some measurements and generally began to get familiar with the equipment. Tomorrow we’ll swap to resistors to get more reliable measurements and start investigating how voltage, current, and resistance are related.

AP Physics: Still on charging capacitors. I think it went well for the most part. We looked at capacitors and resistors in series and parallel to compare the graphs of the current and voltage for each over time. We also went through the derivation and solution to the DE describing the charging for both structures, which also gave us a chance to review Kirchhoff’s laws and solving DEs.