AP Physics 1: SHM Representations
This week was mostly about working problems for simple harmonic motion. I kept the focus on representations, including free-body diagrams, energy bar charts, and motion graphs, which made it a good review of a lot of mechanics topics. I also was really pleased when a student was checking out the topics we have left to cover on the AP Physics 1 Your Course at a Glance and asked if our unit on mechanical waves will have anything to do with the simple harmonic motion we’ve been working on.
Physics: Momentum Card Sort
This week, we worked on transitioning to calculations with conservation of momentum. We started with a collision lab from the Modeling Instruction curriculum, then did Kelly O’Shea’s momentum representations card sort. I’ve had a lot of students asking for me to do example problems before they work problems on paper, which I try to avoid. The card sort seemed to fill that need for a lot of students, while keeping the focus on their sense-making. I definitely want to work on a similar card sort for energy.
AP Physics 1: SHM Labs
We worked on labs to determine what affects the period of objects in simple harmonic motion. I had half the class experiment with pendulums, while half the class used springs. During the board meeting, we did a lot of jumping back and forth between the two experiments; this lead to some good discussion about energy when we saw that mass mattered for the springs, but not for pendulums. I had each spring group use a spring with a different spring constant, which also lead to some good discussion about why the pendulum groups all got the same slope on their linearized graphs, while each spring group got a different slope.
Physics: Momentum Bar Charts
This week, we developed conservation with cart explosions, then worked on using momentum bar charts to represent conservation of momentum problems. After last week, I spent some time talking about the purpose of giving students time to work all (or most) of the problems on paper and warned them I would be unhelpful when they were preparing their whiteboards, then held to it. When we got to mistakes whiteboarding, I required groups to make at least one of their mistakes in the bar charts. While students were working on paper and preparing their whiteboards, I saw a lot more small-group discussion than usual, both within groups and across groups, which was fantastic. During the whole-class discussion, I also got some students speaking up who are usually pretty quiet and one of my classes even got some really good student-to-student exchanges, which have been very rare this year. On Friday’s quiz, students consistently felt really good about their performance. I’m hoping that the positive experience students had whiteboarding these problems coupled with good performance on the quiz will move the class culture in the right direction.
AP Physics 1: Circuits Mistakes Whiteboarding
I forgot to take a picture, but students did some mistakes whiteboarding with yesterday’s problems. We moved quickly enough through circuits that I think I’ll need to make sure I have some circuit materials worked into our review, but students are feeling pretty good about this topic.
Physics: Spring Lab Practical
Students finished up a lab practical finding an unknown mass using both Hooke’s Law and the period on a spring. Students who didn’t include units in their work tended to get two different answers; most groups got a spring constant in N/cm and without units in the calculations, they tended to miss the need to convert. It was a good lesson in the value of units. It also occurred to me I should incorporate this lab into my AP review since students are finding both gravitational mass and inertial mass.
Chemistry Essentials: Balancing Mistakes
We did mistakes whiteboarding with yesterday’s balancing problems. Right now, students mostly seem to be understanding what to do, but need to build up some confidence. I’m really pleased with how well the Mathlink cubes have been working as a manipulative; they are even helping students quite a bit with going between formulas and particle diagrams.
I had a sub today.
AP Physics 1: Circuit Problems
I introduced students to Trevor Register’s KVL diagrams yesterday. Today, I had them work on some problems using the diagram and Kirchhoff’s Laws.
Physics: Lab Practical
Students started a lab practical where they using a spring to find an unknown mass two different ways. I gave them some structure that should steer them to use Hooke’s Law, then the period of the spring. I’ll be curious to see how it went.
Chemistry Essentials: Balancing
Students worked on some problems balancing chemical reactions. At my co-teacher’s suggestion, we got some Mathlink cubes for students to use as a manipulative. I’m curious to see how it goes; when I used some on Tuesday, they seemed to help make balancing more concrete for students.
AP Physics 1: Kirchhoff Board Meeting
We had a board meeting where students shared the rules they’d come up with for current and potential difference, which lead into Kirchhoff’s rules. My students missed some details, especially around current, that I wanted them to see; normally, I would have sent them back to the lab to experiment a little more, but I ended up pointing out the info in the interest of time.
Physics: Mistakes Whiteboarding
We did some mistakes whiteboarding with yesterday’s problems. There are some students who haven’t had me before, so this was their first exposure to mistakes whiteboarding. A few of them started laughing and making some comments when a group clearly had some clearly unintentional mistakes, so I stepped in more than usual and, with help from students who’ve done this before, managed to shift the tone pretty quickly. I’ve been more conscious this year overall that I need to reset the culture in my classroom each trimester, but I dropped the ball today and didn’t revisit what it looks like to contribute during this kind of whiteboard discussion.
Chemistry Essentials: Conservation of Mass Lab
Students did a reaction in a Ziploc bag to see the conservation of mass in action. Students got good results, but balancing the reaction was tricky. The reaction is one of the trickier ones I ask students to balance in this course, so this may have been better near the end of the unit.
AP Physics 1: Kirchhoff’s Laws
Students used PhET’s circuit construction kit to look for patterns in series and parallel circuits. Students were pretty successful at noticing the things I wanted them to notice and I’m looking forward to tomorrow’s discussion of the results.
Students worked on some problems using the spring period equation. We also spent some time on whole-class discussion about the motion graphs for an object on a spring, and tested a lot of ideas using a motion encoder cart hooked to a force sensor with a spring.
Chemistry Essentials: Balancing Reactions
Students used PhET’s balancing chemical equations simulation to start figuring out what it means for a reaction to be balanced. Students were pretty successful at working out the significance of each of the tools the PhET activity provided, along with what it means to be balanced. Even though I didn’t assign the game, a few students decided to play and ended the hour with a lot of confidence and enthusiasm for balancing problems.
AP Physics 1: Coulomb’s Law Whiteboarding
We spent some time doing some practice multiple choice problems, then used whiteboards for a gallery walk of yesterday’s problems on Coulomb’s Law and Ohm’s Law.
Physics: Spring Representations Whiteboarding
Students whiteboarded various representations for an object vibrating on a spring, then we did some discussing to come to an agreement on what those representations should look like.
Chemistry Essentials: Mistake Whiteboarding
We finished going through the whiteboards students prepped earlier this week for a round of mistakes whiteboarding. I’m getting excited to start balancing chemical equations with these students next week; several students have started pointing out when the number of a given element changes between the products and reactants as a sign that something is wrong.