Month: October 2013

My colleague at our sister high school suggested a graphical cityscape lab for AP Computer Science. The purpose of the lab is for students to demonstrate that they can design and implement classes to achieve encapsulation and reuse. The cityscape lab requires students to design and implement at least three classes and then instantiate several objects of these classes to build a cityscape. As always, some student finish the minimum requirements sooner than others. I challenged these students to add an element of randomness or animation to their cityscape. The following is one of my favorites.

One a month, physics teachers in the western suburbs meet to “talk shop,” share ideas, and perform demos. October’s meeting was hosted by my colleagues and I at our high school. We all built a railgun based on a linear homopolar motor as a make-and-take. Here is a video:

  ##magnetism  

After every day I’ve taught, I’ve written a brief reflection about that day’s lesson for each of my classes. Sometimes the reflection is very brief and superficial and sometimes it is detailed and full of wisdom for my future self. I go back and read these reflections each year when preparing for the upcoming unit. Given my poor memory, these have been valuable in helping me to prevent the same mistakes over and over again.

Here’s my reflection for today’s paradigm lab for constant acceleration particle model:

Today’s class was a train wreck. I planned to start the constant-acceleration particle model unit in much the same way as Kelly O’Shea. However, I thought that students viewing the graphs on iPads connected to a single LabQuest 2 would be better than students watching the project image of the LoggerPro screen. I first discovered that the LabQuest 2 only works with Vernier motion sensors and not PASCO ones. I did finally find an old Vernier motion sensor, but it was somewhat temperamental collecting useful data. I was able to get a good run after some positioning adjustments. However, when I had 20 iPads all connect to the LabQuest 2, they wouldn’t all be updated at the same time. Some would display the latest data from the LabQuest 2 and some would be stuck waiting to refresh or showing a previous run’s data. I probably tried to connect too many devices to the same LabQuest 2. As a result, I ended up projecting my iPad on the large screen. At this point, I was basically back to displaying the data for all to see, but I was displaying the Graphical Analysis app on the iPad instead of the more complete LoggerPro display. Today was an example of technology not helping students. I’ll have to clean up my mess on Wednesday when I’m next in class.

I’ll spare you all the photo of the crying students after this lesson.

  ##capm ##paradigmlab ##setbacks  

Today, Physics Club launched and recovered a high altitude balloon. It was our fourth launch and we were joined by a couple of junior high students participating in our Science under the Sea project, a physicist from Fermilab, and an alumni who is a HAM radio expert. The ballon burst just over 105,000 feet. We will have to wait and download the data from the onboard GPS to see if we broke last year’s altitude record. The weather was beautiful and the recovery was relatively easy as the payload landed in a field of corn about half-a-mile from a road.

This morning, we continued with parent-teacher conferences. Most parents visit Thursday night; so, I had time to start gathering the supplies for Sunday’s high-altitude balloon launch. A few parts still need to be tested or assembled, but we are almost ready to go.

We had an institute day today and parent-teacher conferences tonight. I’m located in the physics prep room for conferences. I don’t mind the smaller space and it gives parents some insight into where all the good stuff is stored. The door to the prep room is between room 142 and 143, but it isn’t 143 which is located around the corner! I kind of feel like I’m located at the classroom analog of Platform Nine and Three-Quarters.

Today in AP Physics B, we whiteboarded problems focused on fluids in motion; specifically, the equation of continuity and Bernoulli’s equation. A running joke in AP Physics B is that any problem can be extended into a projectile motion problem. The students extended this problem to involve me shoving another teacher into the swimming pool that was being filled. This evolved into asking how weak would the force of gravity need to be in order for the pool to be filled by the time the other teacher hits the water. I joked that I would share their question with the College Board.

 ##whiteboarding ##pmp 

In AP Physics B, we have started learning about fluids in motion. Today, we explored several examples of Bernoulli’s Principle (my favorite is blowing a time into a cup) and measured the velocity of air blown through a Venturi meter.

Here is the handout for the activities.

Bernoulli Activities by gcschmit

This coming Sunday, we will launch a high-altitude balloon. We just picked this date a few days ago and started preparing last Friday. We have a lot to do, but this year’s launch is less complicated than the last one and we aren’t trying anything completely new. We do however need to update our Arduino-based data logging and cutdown mechanism since it didn’t perform as desired last time. Today during lunch, a student was soldering the cutdown hardware mechanism and I was working on the software. It’s going to be a busy week!

One of several Newton’s 3rd Law activities that students explored today was this setup of 2, 1-kg masses and 3 spring scales connected by string:

Students were instructed to draw free body diagrams for each mass and each scale. They then were asked to predict the reading of each scale. Students that trusted their FBDs made the correct prediction. Students who didn’t most frequently predicted that the scales would each read 20 N. Some predicted that the scales would each read 7 N (20 N split three ways). A great activity to reinforce how powerful a tool free-body diagrams are if they are trusted!

  ##bfpm