Circuits

Day 123: Mistakes Game & Sedimentary Rocks

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AP Physics: Mistakes Game

Students played the Mistakes Game with some electric circuit problems. I noticed students who drew arrows to represent the possible current paths tended to be much more successful, so in my 4th hour I explicitly made that part of the instructions. I also took a few minutes in that hour to give students a series and a parallel circuit to have students rank the resistances to solidify that idea. I think I will start with that in 2nd hour tomorrow.

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Earth Science: Sedimentary Rocks

Student worked on identifying sedimentary rocks using a key. There were some good discussions in lab groups about the fuzzy boundaries between some of the rock types. I struggled a bit with what thinking students could do to go beyond just using the identification key. I think I’m going to run into the same issue tomorrow with the metamorphic rock lab.

sed rocks

Day 122: KVL Diagrams & Igneous Rocks

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AP Physics: KVL Diagrams

I introduced students to Trevor Register’s KVL diagrams and had students start working some problems. I also have students trace the possible current paths on the circuit diagram to give students a visual for Kirchoff’s Current Law. We also had a quiz today, so most groups only got through the problems that were purely series or purely parallel, but there was a lot of great conversation with students pushing each other to be specific in their use of vocabulary.

kvl

Earth Science: Igneous Rocks

Students worked on identifying different types of igneous rocks. The identification key starts with texture and uses some technical terms for the textures, so before students got the key, I had them group their samples by similar texture. This seemed to help students make sense of terms like “grained” and “frothy” as they apply to rocks. It felt a bit disconnected from the work we’ve done on the rock cycle, which feels disconnected from what we did on Earth’s layers, so I’d like to work on a clearer storyline for this unit.

ig rocks

Day 121: Kirchoff’s Laws & Rock Cycle

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AP Physics: Kirchoff’s Laws

Students attempted to apply their patterns to some fill-in-the-blank circuits and whiteboarded statements to describe the patterns they’d found using both the simulation and the real-world lab. It definitely felt more challenging than last year, but I think it was because of how I broke things down to get into a computer lab. Next year, I will get laptops or tablets instead so we can stay in the classroom, then do both the simulation and physical lab for series one day, then do both versions of the parallel lab the next day. That should reduce how much information students are trying to keep track of to make this series of labs more manageable.kvl wb.jpg

Earth Science: Rock Cycle

I modified an activity from the middle school Modeling Instruction curriculum using crayons to look at the rock cycle. I had students make some shavings to represent weathering and erosion, then squish the shavings together for a sedimentary rock. Students then melted their sedimentary rock and let it cool to make an igneous one. Next time, I think I’ll have them use higher pressure, maybe from a stack of books, to get metamorphic rocks in there.

crayon

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

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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.

plicker

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.

category

Day 119: Whiteboarding & Mineral Intro

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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.

stereo

Day 118: Circuit Sim Again & Earth’s Layers

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AP Physics: Circuit Sim Again

Students used PhET’s circuit construction kit to explore Kirchoff’s Laws in series and parallel circuits. I also tried to mimic an extension of an electric field mapping lab by having students place the ground probe of the voltmeter at different points in the circuit, then move the measuring probe around the circuit. I liked that this got students noticing that the total change in voltage is always the same and it got them thinking about what a negative voltage means. On the Kirchoff’s Laws portion of the activity, I saw a lot more variation in how students thought about the patterns than in the past, which was a lot of fun. I was especially impressed when one student pretty much derived the equivalent resistance for a parallel circuit.

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Earth Science: Earth’s Layers

Today, we built on the scale diagrams students made yesterday, adding some information on the properties of each layer. I tried to get some deeper thinking by asking questions like how two layers could have similar composition, but different densities, and it was a little tougher than I expected. I think if I’d primed students with some questions about pressure, that task may have been easier. It bothered me to just state give students information about the interior of the Earth, so I spent a few minutes talking about seismic tomography with my students. Next time I teach the course, I’d love to come up with a lesson to give students an analogous experience.

Day 117: Ohm’s Law & Earth’s Layers

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I almost forgot about my blog post today!

AP Physics: Ohm’s Law

We got out the power supplies and resistors to see if the formula students found for Ohm’s Law in the sim yesterday also works in the real world. Students were getting good results and I overheard a lot of good talk about uncertainty.

Earth Science: Earth’s Layers

Students worked on a scale drawing of the interior of the earth. I like students comparing the thickness of the layers and getting a sense of scale by adding some features like Mount Everest or an ocean trench. The questions are fairly superficial, so I need to think about what kind of deeper thinking I want them to do tomorrow. I do like the way the Mystery Tubes lead into this, since we don’t have any direct observations of Earth’s interior.

Day 116: Circuit Sim & Mystery Tube

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AP Physics: Circuit Sim

Students used the PhET Circiut Construction Kit to start exploring circuits. Students had some great conversations around a few questions about the blue dots I took from the PUM curriculum. I was surprised to hear some students say the blue dots must get used up since batteries die over time, but students were able to test that idea by removing their battery. This lead a few students to connect back to momentum, thinking of the battery as a source of impulse, which I thought was an interesting connection.

circuit

Earth Science: Mystery Tubes

With the start of a new trimester, students got shuffled again. A little over 75% of my 9th graders haven’t had me yet this year, so I will need to make sure I am paying attention to classroom culture and helping students understand what I want from them.

To get students practicing observations and inferences, I had them play with the mystery tubes. In their notebooks, I asked students to explicitly connect each inference to at least one of their observations with an arrow. Several groups were surprised when I told them their sketch of the inside of the tube was a useful inference, so I know I’ll need to do some work with this group explicitly valuing non-verbal representations. Tomorrow, I’ll take some time to connect this activity to the scientific process and how I want to approach this course.

mystery tube.jpg

Day 72: Vector Addition & Electric Power

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AP Physics: Vector Addition

I shamelessly stole an activity that Casey Rutherford shared on Twitter. I gave students some free-body diagrams drawn to scale, and had them use pipe cleaners to rearrange the vectors and do some graphical vector addition. The activity not only reinforced graphical vector addition, but I was pleased with how it drove home the difference between forces that are balanced and forces that are equal.

vectors

Physical Science: Electric Power

Students plugged different light bulbs into Kill-A-Watt monitors to find the power each one used. To emphasize the connection to energy, I also had students sketch energy bar charts for each light bulb, using light and thermal energy as their energy types. This lead very nicely into a comparison of the efficiency of different light bulb types.

killawatt

Day 71: Quiz & Circuits

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Today was our last day of classes before break!

AP Physics: Quiz

Students took a quiz on projectile motion. My collaborative team’s goal is related to experimental design, to I included a problem to give my students some practice and feedback on designing on an experiment entirely on paper. I planned to have them play with some Mystery Tubes after the quiz, but it went longer than I expected, so I will save those for another day.

Physical Science: Circuits

I got out the light bulbs and batteries for students to build real-life circuits and see if the models they developed with the simulation still work. Not all of our light bulbs are identical, and I didn’t check the kits before class, so some groups had bulbs with different resistances. Next year, it could be interesting to use that as a feature, rather than a bug, and ask students to rank the resistance of their light bulbs based on qualitative observations.

circuit