Physics: Compound Circuits

Students continued to work on yesterday’s compound circuit problems. A few students yesterday traced different paths through the circuits using colored arrows to provide a visual cue for which currents should add up, and a lot of students today found it helpful to add that representation. I was really pleased when a student insisted that the last problem, with the most complicated circuit, was the easiest in the set.

Chemistry: Empirical Formulas

Students finished up the lab from yesterday, then worked on some written problems finding empirical formulas. I didn’t take the time to discuss the connections between what the lab represented and what they were doing in the problems, and many students struggled to not only transfer ideas from the lab, but to bring back skills like converting mass to moles. I need to make sure I take the time to help students build those connections.

Physics: Compound Circuits

Students worked on applying Kirchoff’s Voltage Law and Kirchoff’s Current Law to solve compound circuits. A lot of students made use of my colored pencil’s and of Trevor Register’s KVL diagram to help set up their equations. During the labs last week, I had a lot of groups come up with patterns based on ratios (i.e. every resistor in series has the same ratio of potential difference to resistance), but very few students set up ratios in the problems. I found that a lot of groups needed some prompting to think about how the labs last week relate to today’s problems. Next year, I may try doing some compound circuits in the lab or PhET circuit kit as a bridge to pure paper and pencil problems.

Chemistry: Empirical Formulas

Students found empirical formulas for samples of colored beads, where each color represents a different element. My goal was to give a concrete analogy for what is happening in the lab when they find an empirical formula.

Physics: TIPERs

I introduced students to Trevor Register’s diagram for Kirchoff’s Voltage Law, then turned them lose on some questions from TIPERs that we used for the mistakes game. A lot of groups made good use of the KVL diagrams both in their groups and during the whole class discussion. We haven’t done the mistakes game much this trimester, but groups did a nice job of using their initial errors as a basis for their mistake.

Using the KVL diagram

Chemistry: Percent Composition

Students did a lab to find what percentage of a stick of gum is sugar. This is one of the first quantitative labs we’ve done, and students struggled with a question about likely sources of error in their measurements, so that will take some conversation on Monday.