Day 112: Video Analysis on Repeat

Wednesday, 8 February 2017

“Hey kids, I’m going to teach you to predict the future! You can use video analysis to learn about an object’s motion, and assuming it keeps going like that, you can predict details of its motion beyond the short length of track pictured here.”

“So, go get a cart, a track, and your phone. Tell me the acceleration of your cart.”

Where in the past, I relied on more printed labs with detailed procedures, this year, I’m taking a page from the physics teachers of the internet and focusing on representing motion multiple ways. We’ve done three video analysis labs, and every time I ask the kids to divide their papers into four quadrants: describing the motion in words, on a data table, in a graph, and with an equation.

It’s paying off. Pretty much everyone could set up the video analysis in their videos. I even showed them intermediate tricks like setting the coordinate system in a convenient way (like, having the x-axis run along the length of the track).

Then I gave them a quiz on inferring motion from reading graphs. We had near-perfect results with these questions:

  1. Describe the motion on each graph as “object moving forward/backward” AND as “object maintaining/increasing/decreasing speed”.IMG_20170206_134619.jpg
  2. Then, I asked them to match up these velocity vs. time graphs with the position vs. time graphs above. IMG_20170206_134641.jpg

You gotta do stuff a bunch of times for it to be a skill everyone in the room has. That’s why we video analyze all the things this month.

Day 108: What is Free Fall?

Tuesday, 31 January 2017

I wanted to teach them video analysis so they dropped golf balls and learned a little about freefall as well. Later, we went outside and I chucked a bocce ball as high in the air as I could. They filmed it:

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I try to get the students to understand plotting position and scaling on the first go around. These days, I try to do most kinematics labs using video analysis only (as opposed to breaking out the motion detectors or photogates). I do that because the kids get pretty darned good at video analysis after we’ve done it a bunch.

Pro tip: though your computer has a built in camera, resist using it for video analysis. The frame rate and resolution aren’t that great.

By the way, my video analysis software of choice is Logger Pro because it comes preloaded on the student computers. A good free alternative is Tracker.

Day 104: Buggy Crashes

Wednesday, 25 January 2017

We started kinematics yesterday. I gave students a tumble buggy, a meter stick, and told them to take their phones with them. I asked them to describe the buggy’s motion in words, in a data table, on a graph, and with an equation.

Today, I asked if they were confident in yesterday’s work. “Yes!” they said. So I asked them to go head to head, predicting the collision point. Here’s one group’s collison:

Prediction: buggies will collide at the little explosion sign in the middle.

A post shared by Megan Hayes-Golding (@megtheteach) on

Most solved by figuring out the position of each buggy at 1s, then 2s, then 3s, then realized buggies would crash between 3 and 4 seconds, so they guessed the rest of the way.

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One group decided to solve in the more elegant way — by solving a system of equations. Finally, we all discussed why our predictions weren’t perfect.

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We had a great two days back and I’m eager to introduce them to accelerated motion.

Day 102: Lamps & Last Day of JanTerm

Friday, 20 January 2017

The project was to build a lamp from a lamp kit and bulb provided and no more than $10 in materials from a thrift store. The goal is to repurpose the materials in an interesting and possibly unintended way. Here are some of my favorite lamps from the 2017 Makers:

And with that, #JanTerm17 is a wrap. Three weeks, 20 students, three teachers, and eight projects that span many Maker competencies.

Day 101: Photo Booths

Thursday, 19 January 2017

Today is the day we finished building our photo booths and shared them with the school community. I worked with some students to build the Raspberry Pi with a touch screen and camera attached and my colleagues worked with the rest of the class to build actual booths, backdrops, and props.

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My first Raspberry Pi project. With a well-documented set of directions, students completely unfamiliar with the Linux command line can do this work.

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This group of Makers was amazing. They were willing to be silly with me in the photo booth.

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A photo booth in its natural surroundings.

A major part of this project was to engage our school community in a project we created. Last year, the students chose to build a game called snookball. Feedback from those kids this year was that our photo booths were a better choice.

Day 96: Frustration in Reflection

Wednesday, 11 January 2017

Is frustration a good thing? How can I set my students up to learn from rather than be stressed by frustration? JanTerm is a great time to work on this problem.

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This WeevilEye led to growth for one Maker student.

One student, a freshman, wrote the following in her post-project report:

During our visit at Decatur Makers, we learned how to solder while building our WeevilEye project. During the process, I made a mistake and applied the solder on the wrong side, resulting in the need to remove the solder so I could start over. Even though I was very frustrated, one of the people at Decatur Makers introduced me to a solder vacuum. After the solder melted into a liquid, the solder vacuum sucked up some of the solder making it so that I could slip out the wires and start over.

I’m struck by her use of frustrated. This kid definitely learned from the experience. She got to use a solder vacuum and certainly saw that it’s a cool tool. Looking back, I’m sure she’d say the frustration was worth it. But in the moment, in the moment my heart aches for her frustration.

I know well enough to let the kids work through their frustrations — that learning happens in those moments. But dang, I wish I had a better way to set kids up for these moments.

Side note: JanTerm is a whirlwind of a course — 13 days of class with 20 students and three teachers. Grading student work is the hardest part for me. Days are exhausting and I don’t stop from 8am to 3pm. Now that I’ve finally started reading some student work, I’m impressed by kids who turn in work like I quoted above. This kid did a little searching to learn about other types of soldering iron tips (conical tips are better for smaller components but a chisel is better at delivering even heat) as well as surface-mount vs through-hole soldering.

Today in class we began making the 8×8 LED Matrix project. The finished project should look like this:

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Most of us have very little soldering experience, so it’s a stretch. In the first half hour, I was pretty sure it was too much for them. But then things started to fall together. Students figured out their own techniques and several pairs managed to solder and test all 64 LEDs.

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Soldering 64 LEDs to a perf board is a huge task when all you’ve previously soldered is the WeevilEye from a week ago.

Day 95: PVC Trebuchets

Tuesday, 10 January 2017

For Tuesday this week, we built trebuchets from PVC. Two motivations led us to choose this project: 1) throwing things is fun and 2) PVC is a great material for makers to build with.

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This picture is absolutely candid. Nothing staged about it.

To build, we used the instructions for the PVC Trebuchet Instructable. What I liked about this plan was the variety of PVC fittings the kids would get to use. Students worked in groups of four to assemble per instructions.

My teaching colleagues and I had to show kids a few details, including using epoxy for the first time, how to use PVC primer & cement, as well as how to bend a nail using channel lock pliers.

There’s quite a bit of fine tuning that happens with the angle of the nail used in the release mechanism. I wish we’d had another hour to mess around with it. Since most of y’all don’t have a JanTerm, I hope y’all physics teachers are eyeing the project for projectile motion. Do it! These things could probably be built more efficiently by making the cuts in advance. I bet you could do it in about 2 hours.

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