This week, we worked on problems and calculations for projectile motion and free-fall. A lot of students were rusty on velocity vs. time graphs (like we haven’t used them much in a while or something!), so it was helpful to revisit. I also continue to really like projectile motion as a wrap-up to linear mechanics since we had a chance to revisit pieces of each major topic so far. I was out sick for a day, which made it tough to fit in the practical I usually do while staying on track for pacing. I think the practical could be good for a review in April, especially since I’ve got some ideas for extensions to connect the lab to more concepts.
Physics: Impulse Problems& Risk Taking
We spent most of this week working problems using momentum and impulse and discussing them with mistakes whiteboarding. This week, I was particularly aware of two common behaviors during problems and whiteboarding that suggests students are still wary of taking risks in my classroom. First, when working the problems on paper, I had a lot of students who got off-task if I wasn’t at their table and were really resistant to sharing their thinking if I was. Second, most of the mistakes students picked for mistakes whiteboarding were in parts of the problems that relied on familiar representations, like vector addition diagrams and velocity vs. time graphs, rather than in the new material.
Recently, I had a conversation with an administrator about classroom environments that encourage academic risks and we agreed that before students can take a risk, they need (1) to feel safe and to know the stake are low and (2) a clear sense of how they will benefit or what they will gain, ideally regardless of the outcome. I’m pretty sure I need to put in work on both of those criteria. Some students who I know really appreciate the discussion that comes from mistakes on new material stuck to mistakes on the familiar content, which tells me they aren’t feeling as safe as I ‘d like. Several of the students who were off-task doing problems on paper find the whiteboard discussions extremely valuable, so I think they just didn’t see a benefit to taking the risk or effort of working through their confusion when we were still on paper. All of this tells me I need to keep working to make sure both requirements for academic risk taking are present in my classroom.
Next week are trimester 1 final exams. In both my courses this week, we wrapped up our last topic and started reviewing for the final.
AP Physics 1: Goal-less Problems
I really like Kelly O’Shea’s goal-less problems, so I decided to try that as a final review. I went through the released free-response problems and took the diagram and prompt from several that could fit with topics we’ve done so far this year. We focused on identifying applicable models, sketching additional diagrams, and reading strategies. Students especially liked a strategy to cross out information in the prompt that is accounted for in the diagram, especially once we started annotating diagrams to get rid of even more text.
Physics: Units vs. Variables
Students worked on, then whiteboarded a fairly standard final review packet with written problems. One of the biggest things I worked with students on is the difference between a variable and a unit, which has been a recurring challenge this year. For example, in the force of gravity equation, a lot of students are reading “g” as grams, rather than as 10 N/kg. I’ve been working on talking frequently about variables as representing a quantity and quantities as a number with a unit that describe something we can measure or calculate. Going into tri 2, I need to keep thinking about how to help students make sense of when a letter represents a quantity and when it represents a unit that is part of a quantity.
The 2019 free response were released last Thursday. I always have some students interested in discussing the problems, so I offered to go through my solutions with interested students today. The students who opted into the discussion said they struggled in the spots I expected them to, but felt really good about the rest of the problems. We’ll see for sure in July!
Physics: Curved Mirrors
We discussed the results of Friday’s lab, especially some rough ray diagrams I had students sketch. We also got a nice visual of the focal point using a big concave mirror, a ray box that fires several laser beams, and some chalk dust.
Chemistry Essentials: Activity Series
Students combined several different metals and nitrates to rank the reactivity of the metals. One of the reactions is fairly subtle, but students did a nice job of recognizing what was being produced in each reaction.
A lot of my students were gone today for the AP Literature exam. I took some time to introduce the final project students will be working on, then we talked a little about how they felt the AP Physics 1 exam went. Most students felt better about the free response than the multiple choice, which is pretty consistent with what I’ve heard from past years.
Physics: Mirror Mistakes
We did some mistakes whiteboarding with ray diagrams for plane mirrors and students pretty quickly got the hang of the diagrams. One student declared we need a song for mistakes whiteboarding; I’ll be sure to update if we come up with one.
Chemistry Essentials: Reaction Types Mistakes
We did mistakes whiteboarding with some problems for recognizing different reaction types. Students were very successful at making sense of these problems and I hat pretty minimal intervention.
My favorite dedicated review activity is model summaries, where students whiteboard key diagrams and formulas for each model. Students have those diagrams in their toolkits, so today was mostly about reminding students to use them and reassuring them they know how to use these tools.
Physics: Reflection Lab
Students collected data for a relationship between the incident angle and reflected angle in a mirror. We did the pre-lab discussion yesterday, and I did have to get ornery about reminding students to go back to their notes from that discussion to get started, but the lab went very smoothly from there. We’d bought some laser pointers a year or two ago, so I had students use those instead of pins in cardboard, and I really like that students could see the light rays directly.
Chemistry Essentials: Reaction Types Reading
I’ve got some ideas for a card sort to introduce reaction types, but ran out of time to put something together and went back to a reading in our textbook. I had students write definitions for each reaction type using both the textbook language and their own words and I had students come up with their own larger categories for the reaction types, both of which lead to some good discussion.
Students used Pivot Interactives to explore collisions that involve angular momentum. I especially like the activity they have with a marble fired at a wood block since it provides an opportunity to review linear momentum, as well as discover a relationship between torque and angular momentum.
Physics: Ray Diagrams
Students sketched ray diagrams to explain their observations in Friday’s lab. Students were able to make good connections between their ray diagrams and their observations.
Chemistry Essentials: Limiting Reactants
Students whiteboarded some limiting reactant problems, emphasizing the particle diagrams that could be used to solve the problems.
After a short quiz, we used Plickers to review some multiple choice. There was a lot of good discussion about the problems and some good test-taking strategies also came out of the conversations.
Students made observations and dew ray diagrams for some pinhole viewers. They had some trouble getting images at first, but, once they got the hang of it, seemed to enjoy the lab. It was a nice, sunny morning, so we went out the back door of my classroom to look at things, but it was also chilly, so most students went back inside when they were drawing ray diagrams.
Chemistry Essentials: More Limiting Reactants
Students did some limiting reactant problems involving polyatomic ions. All of the problems were ones that could be solved by drawing a particle diagram, and students seem to be embracing those as a problem-solving tool.