Simple Harmonic Motion

Day 133: Board Meeting, Pendulum Practical, & Percent Yield

/ Marta R. Stoeckel / Leave a comment

AP Physics: Board Meeting

Students whiteboarded their results from yesterday’s Pivot Interactives activity. Students spent a lot of their time yesterday on whether the location of the collision affects whether linear momentum was conserved, but had a lot of interesting approaches and good discussion about that question. For the portions of the activity specific to angular momentum, I ended up much more teacher-directed than I like since I will be out tomorrow and am feeling the time crunch of the looming AP exam.

Maker:S,Date:2017-10-21,Ver:6,Lens:Kan03,Act:Lar02,E-Y

Physics: Pendulum Practical

Students finished yesterday’s practical, then were tasked with finding the period of a pendulum without using a ruler or meterstick. Not surprisingly, most students declared the pendulum practical was much easier than the spring one.

Maker:S,Date:2017-10-21,Ver:6,Lens:Kan03,Act:Lar02,E-Y

Chemistry Essentials: Percent Yield

Students predicted how much carbon dioxide should be produced in a reaction between baking soda and hydrochloric acid, then found the percent yield by measuring how much mass was “lost” during their reaction. I like that this lab circles back to conservation of mass to measure the mass of gas produced, but a lot of students had trouble connecting the lab to the stoichiometry problems we’ve done, so I need to think about how the layout and wording of the lab may be making those connections more difficult.

chem yield lab.jpg

Day 131: Test, Whiteboarding, & Quiz

/ Marta R. Stoeckel / Leave a comment

AP Physics: Test

Students took a quiz covering several learning targets that was really long enough to call a test. I’ve been including a self-assessment on my quizzes all year, and today I tried an idea I’ve been toying with to break each learning target being assessed into sub-skills. It didn’t have much impact on how students responded to the reflection I ask for, but students did say they found the breakdown of each learning target helpful. I need to think about good structures to share that with students prior to the assessments.

Physics: Whiteboarding

Students whiteboarded yesterday’s problems. I went with a consensus-building approach, where all groups whiteboarded the same thing, then we talked as a whole group to agree on the answer. There were a few things I could tell students were rusty on, but students were able to make the connections I was after.

spring wb (1).jpg

Chemistry Essentials: Quiz

Students took their quiz on stoichiometry. Several students, when given the mass of one reactant, asked if they could assume they had enough of the other reactants, which I found really interesting since that question hadn’t come up before. Regardless, that question will be a perfect lead-in to limiting reactants.

Day 130: Rotational Inertia, Springs, & Whiteboarding

/ Marta R. Stoeckel / Leave a comment

AP Physics: Rotational Inertia

Students worked on data collection for the rotational inertia lab we started yesterday. A lot of groups are setting up spreadsheets to streamline the calculations, which is great. However, this lab is time-consuming enough that I want to spend some time this summer looking at alternatives or trying to simplify it.

Maker:S,Date:2017-10-21,Ver:6,Lens:Kan03,Act:Lar02,E-Y

Physics: Springs

Students worked on connecting models from earlier in the year to the motion of springs. A few students struggled to get started with the free-body diagrams, but most were able to work through and make the connections I was after.

On a side note, I talked to one lab group about their pre-calc homework. They had some problems involving free-body diagrams for blocks on a ramp, but were thrown off by some differences in language and notation. I should find a time to connect with the pre-calc teachers to see if there are ways we could do a better job of building on each others’ classes.

Chemistry Essentials: Whiteboarding

Students whiteboarded yesterday’s problems. Since the problems are on the long side, I decided to do a gallery walk today. Stoichiometry seems to be clicking for a lot of students.

Maker:S,Date:2017-10-21,Ver:6,Lens:Kan03,Act:Lar02,E-Y

Day 129: Rotational Inertia, Board Meeting, & Stoichiometry

/ Marta R. Stoeckel / 1 Comment

AP Physics: Rotational Inertia

Students started a lab to find what affects the rotational inertia of a T made out of PVC. The number crunching on this lab gets hairy enough that I want to reevaluate this lab for next year. One option would be to have students apply a force by pulling with a spring scale or force sensor rather than dropping a hanging mass.

rot i.jpg

Physics: Board Meeting

Students whiteboarded their graphs for the spring period lab. The results for spring constant didn’t come out as nicely as I hoped; a lot of groups struggled to find that value accurately. We ended up using units to reason through how spring constant plays in.

spring wb.jpg

Chemistry Essentials: Stoichiometry

Students did some written stoichiometry problems. Many of them needed more coaching than I’d hoped, but they were able to connect to yesterday’s lab and use particle diagrams to start putting the pieces together.

Day 128: Whiteboarding, Springs, & Stoich

/ Marta R. Stoeckel / 2 Comments

AP Physics: Whiteboarding

Students whiteboarded some torque problems. I can tell the last week or so has been a little disjointed; I had a lot of students trying to use Universal Gravitation to find the force of gravity in the torque problems and some were having trouble with what we meant by the radius. I spent some time talking with those groups how to decide when to use each version of the force of gravity equation, and that helped resolve things.

Physics: Springs

Students wrapped up collecting data for the period of a spring. I overheard a great conversation in a lab group; one student was griping a little about collecting data for the mass since he was convinced it shouldn’t matter based on the pendulum lab. Once they had a few data points, though, there was a moment when he lit up and made a beautiful connection to energy transformations to explain why mass mattered.

Maker:S,Date:2017-10-21,Ver:6,Lens:Kan03,Act:Lar02,E-Y

Chemistry Essentials: Stoich

We got the hardware out again to start stoichiometry. Students assembled nuts, bolts, and washers into “molecules” and predicted how many grams of each molecule they should have after a chemical reaction. The manipulatives seemed to help a lot of students wrap their heads around what is going on in a stoichiometry problem, which I’m hoping will translate into success with the paper and pencil problems tomorrow.

stoich.jpg

Day 126: Universal Gravitation, Pendulums, & Quiz

/ Marta R. Stoeckel / Leave a comment

AP Physics: Universal Gravitation

We discussed the results of the universal gravitation lab today. Once we got the inverse-square relationship, students quickly recognized the slope of their graphs seemed to be connected to the stellar mass. Prior to class, students entered their slopes and stellar masses into a spreadsheet, so I projected the data and sorted it to confirm the biggest slopes went with the biggest stellar masses. I also graphed students’ slopes vs. stellar mass to get a pretty good value for G.

chart (1)

Physics: Pendulums

Students whiteboarded some problems from yesterday connecting pendulums to other models we’ve used so far this year, including momentum, forces, and energy. A few students needed some reminders, especially about the direction of tension forces, but were very successful in the end.

pend wb.jpg

Chemistry Essentials: Quiz

Students took a quiz on molar mass and balancing equations for chemical reactions. Based on a quick glance at their work and input from the para who worked with special education students on the quiz, I think I’m going to see a bi-modal distribution. I’m planning to start stoichiometry, and need to think about how I’m going to support the students who are still struggling with molar mass and balancing reactions when we are starting to use those skills together.

Day 125: Board Meetings & Molar Mass

/ Marta R. Stoeckel / 1 Comment

AP Physics: Lever Board Meeting

We had the board meeting to discuss the results of the lever lab. A few groups were quick to notice the slope slope on the force graph was the ratio of the distances to the pivot, while the slope on the distance graph was the ratio of the masses they used, which lead nicely into a definition of torque.

lever wb.jpg

Physics: Pendulum Board Meeting

In my first hour, the board meeting was pretty rough with a lot of very long silences. I forgot this was the first board meeting of the trimester and about half of my students had the other physics teacher last tri, so I should have taken more time to set up the board meeting. My other hour is a little more talkative to begin with, but I also spent more time prepping for them discussion and things went much better.

Chemistry Essentials: Molar Mass

Students applied molar mass to some real-world problems, such as finding how many moles of chalk it took to write their name. Students are approaching the calculations for number of moles very algorithmically without much sense of why they divide the numbers they do. I need to think about how to make the why more apparent; I’ve discussed some analogies, such as bank tellers counting pennies by weight, but I wonder if it would be helpful to actually carry an analogy out in the lab.

chalk.jpg

Day 124: Levers, Pendulums, & Molar Mass

/ Marta R. Stoeckel / Leave a comment

AP Physics: Levers

Most students did not finish their data collection on the Universal Gravitation lab, so I decided to postpone the discussion. A lot of students prioritized data collection on Monday, then ran into trouble doing calculations in a spreadsheet and weren’t comfortable asking for help electronically since they don’t have much experience with that. It was great to see, however, how many students were enthusiastic about trying their hand at spreadsheets.

In place of the discussion, we jumped ahead to levers to introduce torque. Students first placed the clamps at set positions and found a relationship between the mass hanging from one side and the force required to balance the lever. Next, students picked two masses to use and found a relationship between the distances from each mass to the pivot required to balance the lever. One student commented the second part of the lab reminded her of using a triple beam balance.

lever.jpg

Physics: Pendulums

Students predicted the period of a pendulum at the main entrance using their data from Monday. A lot of groups used a linear fit and predicted a larger period as a result. We didn’t get to the board meeting today, so tomorrow we’ll have a chance to get into why that happened.

pendulum big

Chemistry Essentials: Molar Mass

Students practiced finding molar mass and the number of moles in a sample. When students get stuck, particle diagrams have been a huge help since they force students to break down what the formula actually represents.

Day 122: Universal Gravitation, Pendulums, & Formula Mass

/ Marta R. Stoeckel / 4 Comments

Today was our first day back from spring break! We have kind of an odd start to the week since tomorrow freshmen and seniors have an off-campus learning day to accommodate state testing for sophomores and juniors.

AP Physics: Universal Gravitation

Students worked on an activity Lucas Walker presented at AAPT last summer using exoplanet data to find a relationship between centripetal acceleration and orbital radius. I was nervous about having students calculate the orbital velocity and acceleration in a spreadsheet since most of my students don’t have much experience with spreadsheets, but my students were very willing to dive in using the resources I provided and were very successful with the calculations.

Physics: Pendulums

Students collected data to model the impact of weight, drop angle, and mass on the period of a pendulum. I’m continuing to see students much more confident in their physics abilities than even the end of last trimester, and working more independently as a result.

pendulum.jpg

Using the environment to make measuring release angle easier

Chemistry Essentials: Formula Mass

Students started making sense of formula mass by predicting the mass of various combinations of nuts, bolts, and washers. I wanted to give them something pretty concrete they could test directly in the lab before diving into true stoichiometry. When we shifted to chemical formulas at the end of the hour, a few students got tripped up if they skipped the particle diagram, but the math was pretty obvious to everyone once they got that step.

molar mass lab.jpg

Day 85: Whiteboards Galore

/ Marta R. Stoeckel / Leave a comment

AP Physics: SHM Whiteboarding

Students did some whiteboarding to discuss yesterday’s trio of simple harmonic motion. There was some good discussion about whether the net force on each object is constant or changing for each object. In one section, I asked students for free-body diagrams and vector-addition diagrams to resolve that debate and in the other section, I asked them to sketch velocity vs. time graphs. The velocity vs. time graphs were much more effective for resolving the disagreement.

shm wb.jpg

Physics: Kinetic Energy Board Meeting

Students whiteboarded their results for the kinetic energy lab. This time, I didn’t specifically prompt them to linearize their graphs and only some groups tried plotting change in height vs. velocity squared, which made for a nice discussion.

ke (1).jpg

Chemistry Essentials: Freezing Lauric Acid

Students finished making their graphs, then we discussed the results of the lauric acid lab. A lot of students had trouble with a question about whether you can add energy to a system without changing the temperature, which reinforces my impression that many of those students are having trouble making sense of what the representations we’re using mean. I also forgot I wanted to have my students move before we shifted to whole group discussion and didn’t think of it until after class. Enough groups had trouble shifting to whole class mode that I need to make a note for next time.