Day 125: Plickers & Earth Resources

AP Physics: Plickers & Quiz

Between now and the AP exam, my plan is to spend Fridays on multiple choice practice, followed by a quiz. We used Plickers again, with students first voting on answers individually, then talking to a peer before voting again; its really interesting to see how their answers shift with this process. I picked several problems where thinking in terms of a system’s center of mass is useful, and students seemed to grasp that idea, though we will need to revisit to make sure it is solid. There were a lot of great conversations along the way.


Earth Science: Earth’s Resources

I ended up doing some pretty traditional notes to address the learning targets on Earth’s resources. I’d love to put together an activity where students have to argue whether a certain mine or pollution source is worth it (come to think of it, the proposed PolyMet mine near the BWCA would have made for a great Socratic seminar or philosophical chairs), but I ran out of time to prepare something for this year. My students didn’t mind the notes; it turns out several of them had a test next hour in AP Human Geography over a lot of the same material.

Day 120: Kirchoff’s Laws & Rock vs. Minerals

AP Physics: Kirchoff’s Laws & Plickers

I split the class period today into two halves. In the first half, we got out resistors and power supplies to do the real-world version of the Kirchoff’s Laws lab students did on Wednesday. My directions were to see if the patterns they’d found Wednesday worked with today’s materials. I used the same slide as last year, but students had a much harder time figuring out what to do this year. I think the problem is we spent yesterday whiteboarding a different lab, while last year I kept the simulation and real-world versions of Kirchoff’s Rules back-to-back. Next year, I think I will take advantage of my department’s iPads and the HTML5 version of the sim to do it in my classroom. Then I can split up the labs by series and parallel, rather than by simulation and real-world and working around when I can get a computer lab.

The other half of the class, we used Plickers to revisit some multiple choice problems from last tri’s final exam. One problem asked why the speed of a projectile does not change at the highest point. After talking to some other teachers, I really like thinking about that one from an energy perspective, using the idea that a force perpendicular to the motion will not change the energy. To drive that home, I used a mallet to get a bowling ball going in a circle so we could talk about whether the force from the mallet changed the bowling ball’s energy.


Earth Science: Rocks vs. Minerals

Students used their work from yesterday to identify some of the key differences between rocks and minerals. Since the book of stereograms students used yesterday also had a gem section, I included those in our discussion. Students pretty quickly recognized they had trouble identifying characteristics distinguished minerals and gemstones, which lead nicely into the idea that gems are just particularly valuable minerals.


Day 119: Whiteboarding & Mineral Intro

AP Physics: Whiteboarding

Students whiteboarded their results for the Ohm’s Law lab and an electric potential difference activity I had them try in yesterday’s sim. Students plotted voltage vs. resistor with the multimeter’s ground probe in several different positions to see the change is always the same. The analogy between gravitational potential and electric potential doesn’t seem as clear for my students as in the past, so next year I might go back to having students map electric potential.epd

Earth Science: Mineral Stereograms

I did a few notes on what caused the early Earth to melt and form layers. Afterward, students spent some time with books of stereograms of rocks, minerals, and gemstones. I wrote some questions to get students thinking about the key characteristics of each category and it was fun to listen to some of the things students were noticing.