Passion for Physics and Pedagogy

There are days when the demands on my time from obligations outside of my teaching responsibilities are too great. It means that I don't prep as much as I should, that I try to rush through things or that I default to talking too much. All of that happened this week.  Monday, AP Physics needed to review an in-class problem set from Friday and their weekend "Opportunity for Physics Practice" aka OPP (suggested HW) and I felt rushed. I wanted to make sure they had time for an in-class practice problem of a different sort. Usually, when we review work they have completed individually or in small groups I'm still calling on students. They can help explain an answer that is already shown or be asked about some hypothetical that is related like "In this problem the force was up the incline but what if it was down instead?" I realized afterwards that I felt so rushed getting through the review that I hadn't included students in the conversation. It's not ne...

I was so excited to try this, I've thought about doing it for years but seemed to never have the time. My AP C students do an Atwood's Machine lab that I've adapted over the years. The original lab came from my predecessor who had students use two identical hanging masses and one small mass. I've been using 200 grams for the "identical masses" and a 20 gram mass as the small one. The students used a known fall height and stopwatch to determine the acceleration with the small mass on one of the larger masses and then with the other in case the two identical masses weren't actually the same. They used a smart pulley with a Vernier photogate so the second part of the lab asks them to find the slope of the velocity-time graph as another way of finding the acceleration. The second day challenged students to find the mass of one penny using the same method. Instead of the small mass, students used a stack of four pennies (being sure to have them all before or af...

There is a problem in my 10th edition of Halliday, Resnick & Walker that asks students to determine the force read by the spring scale in this image: Prior to trying this problem, students are asked to complete this desmos card sort , originally written by Brian Frank. I asked students to complete it individually, without collaboration, which is hard for them. I tell them that I'm not grading it for accuracy. Then students attempt this textbook problem in groups. The salami in the problem is 11 kg , which I start the discussion by putting in context for them. We joke its more like a holiday ham than a salami.  As we review the problem, students have no problem agreeing the scale reads 110 N (when g is 10 m/s^2) in the image (a) and (b) but start to disagree with their answers for (c). I ask students to raise their hands to vote if they think the spring scale will read 0 N (the misconception that the forces balance and therefore the scale reads 0 N), 110 N (the weight of one sal...

 I was inspired by this Darek Dewy Twitter/X post  he used to demonstrate the contact forces between two boxes using a balloon. He labeled one box "H" that was "Heavy" and the other "L" for "Light." A constant force was applied by a mass attached by a string over a pulley. You can see the balloon being squished between the two boxes, more so when the lighter box is trying to push the heavier one than the reverse.  The first time I tried this I planned to demo it. Then I remembered I had plenty of bricks and plenty of blocks. I put a brick and a block on a tray with a partially filled balloon (so that it fits better between the two) and set them out on my student tables.  I invite students to make a sideways sandwich with a brick on its long side, the balloon and then the block. I ask them to push the system from the block side then from the brick side and make observations. Students experiment for awhile and observe the balloon squish different a...