# Day 137: Universal Gravitation & Glacier Video

After no classes yesterday due to state testing, we got back in the swing of things today.

AP Physics: Universal Gravitation

Today continued quick and dirty coverage of some topics on the AP exam that we haven’t really addressed yet. Today, I asked students whether uniform circular motion or free fall is a better description of the Moon’s motion, and students went very quickly to wanting to find the acceleration, so I gave them the Moon’s period and orbital radius, and got out of the way. This served as a nice refresher on circular motion. Once students got a tiny acceleration, we reasoned that a 1/r2 relationship might make sense for gravity and checked that against gravity at Earth’s surface and get to the Law of Universal Gravitation.  Then, since most of my students saw Coulomb’s Law in chemistry, we used the parallels with gravity to make sense of that formula.

Earth Science: Glacier Video

With conferences tonight, I went ahead and showed the video in the curriculum for today. The video was about the data sources glaciers can provide, which got me thinking about how to have students explore those data sources in the lab. For glacier movement, I’m wondering of something like gak could be used to simulate a glacier, maybe with food coloring drops or toothpick flags to track specific points. For the ice cores, I was thinking it would be really cool to find some scale photos of actual ice cores, especially if I could find a way to have students compare the core data to weather data for that year. Of course I thought of all this while watching the video, rather than last night while I stared at the curriculum materials. Oh well.

# Day 133: Standing Waves & Glaciers

AP Physics: Standing Waves

Today started the standing waves unit. I gave a quick overview of standing waves using a simple sim in Desmos, then we got out the wave generator to collect data for a relationship between wavelength and frequency. To save time, we collected data as a class, but students felt very little connection to the results. Last year, I had students use a Direct Measurement Video to get the same kind of data, then used the wave generator to test some ideas, and I think I’d like to go back to that approach next year.

Earth Science: Glaciers

Students used the textbook to dig into how glacial features are formed. While I wish I’d been able to come up with something more tangible, there were some good conversations about how to effectively use the textbook.

# Day 132: Problems & Glaciers

AP Physics: Problems

Students worked on some oscillating particle problems. Students had some really good discussion about a cart on an angled ramp oscillating on a spring; a lot of groups really dug into what should happen when the angle of the ramp changes. At the end of the hour, we tested their predictions. I wasn’t paying much attention to when I started data collection, but still got a set of graphs my 2nd hour considered applause-worthy.

Earth Science: Glaciers

I gave students a brief overview of some glacial features, then had them use some sand in the stream tables to make a recreational area with a variety of glacial features. Students liked the activity, but they did not connect the vocabulary to how the features form or how they are related. I think I’d prefer to do this at the end of a glacier unit, where students would have the background to tie the features they are using together. At this point in the unit, I’d rather focus on how these features form to give some basis for naming them.