Day 12: Organizing Kids’ Thinking

Thursday, 28 August 2014


A big question for me as a teacher of high school freshmen (ages 13-15) came up today: is it my job to model organization of notes when I lecture, demo, or otherwise speak to the class? The new freshmen seem to think so.

So we’re talking about wave reflection and interference when one kid asks me for what is essentially an outline. I had been building up these ideas sequentially but she wanted to know how many items there would be up front. As in, “there are two types of wave reflections and those are…” I hadn’t done that in the past because it felt like revealing spoilers.

How much responsibility does a lecturing teacher have to outline notes for students at ages 13-15?

I feel obliged to mention here that I don’t lecture that much, lest y’all think I’m one of those teachers.

On this day last year: Snakey Standing Waves

Day 11: Lending a Hand to Math

Wednesday, 27 August 2014


This just in: Math class pillages physics room for class materials!

My colleague is doing Barbie Bungee as a lesson on regression and she needs measuring sticks and tapes. I was happy to oblige because data collection & analysis in Algebra II classes is something I heartily endorse. On Friday, I’ll go watch the big drops.

The other big deal today was the organizing meeting for our FRC Robotics team, the WiredCats. I walked into the room after school and was greeted by this crowd of new and old faces:




The senior team members will start holding their fall training modules in the next month. With coach support, they’ll teach junior team members how to wire the robot, use the shop’s machines, design with CAD, implement pneumatics, write robot code, and write a business plan.

This day last year: Standing Wave Vines & Snapchats

Day 10: Great Warmups

Tuesday, 26 August 2014


In two of my classes, the warmup: What is ultrasonic sound? Who is Banshee from X-Men and what’s his power?

Pictured above, the warmup in the other two: Rank the pictures waves from greatest to least wave speed. (Given wavelength, all frequencies are identical, and amplitude.) Our first ranking task and it was a great success!


Ms. P, librarian, shares about library resources available for the musical instruments project. Kids write a 3-5 page research paper for this one.

Day 9: Seating Choices

Monday, 25 August 2014


Interesting. Freshmen still segregate by gender when given the option to choose their own seats. In case it’s not 100% obvious in this picture: all the girls are on the left and all the boys on the right.

Today, we wrapped up our wave properties lab, reviewed quiz results from their first real physics quiz, and I answered questions about their musical instrument projects (more on that tomorrow).

Day 8: Quiz Corrections

Friday, 22 August 2014


All four sections of physics took their first content quiz on Moodle. Kids are getting their first taste of how I dole out partial credit, how Moodle quizzes work, and (oh yeah) working on some physics.

Above is a quiz question straight outta Moodle and some exemplary student work + corrections. My directions to the kids: take the quiz, hit submit, put down the pencil, get a colored pen, correct anything you now know to be wrong. This is a tricky process to accustom kids to — I think it’s too many things to consider at once. Next year, I’m considering easing them into this process with a little more structure.

The second half of class was devoted to our wave properties lab. Here’s one group figuring out a longitudinal wave’s speed in a giant slinky:

See also: my other 180 posts that mention corrections

Day 7: Wave Lab

Thursday, 21 August 2014


Two classes had their first chunk of time on the wave properties lab. I tweaked this lab significantly from last year and am largely happy with the improvements. My regret is doing this lab after we took notes and went all traditional on wave properties. It would’ve been so much better up front on the first few days of classes.

Also, anyone know how to get a knot out of a giant slinky? Ugh, why do the kids always destroy these things?

Lab #1: Wave Speeds & More (PDF | Word)

Day 6: Making Waves

Wednesday, 20 August 2014


We grouped up and started our first lab, this one on wave properties like speed and wavelength. Above, kids try to find their lab partners via Frank’s subversive lab grouping activity. My only struggle with this otherwise awesome method is that there are 24 cards in the deck and my classes rarely have that number. My solution is to post the spares up around the room and ask kids to consider them as people.

Day 5: Visualizing Wave Movement

Tuesday, 19 August 2014

the wave

What the heck is going on in the above picture? It all started with my top 5 teaching challenge this week: kids don’t want to believe that in a transverse wave, the particles of the medium vibrate perpendicular to the direction of wave propagation. I first showed this awesome GIF:

Many of the kids described that the dots were moving left to right. So I asked for volunteers who didn’t mind holding each other’s hands. Each hand-hold became a dot from the animation. I gave them a minute to coordinate, then asked the whole class to watch the wave being sent along the line.

That great animation above came from ISVR animated GIFS of wave properties (and you thought this format was only for expressing your reactions with pithy movie clips).

Day 4: Velocity of a Wave

Monday, 18 August 2014


The idea I wanted to get across: a wave’s speed depends on the medium through which it travels, not the wave’s frequency or wavelength as v=\lambda f might imply.

The setup: meter sticks, stopwatch, ring stand, string, and a few inches of duct tape.

In class: Get the kids to figure out the speed of a longitudinal pulse with the materials you’ve laid out. Then ask if anyone thinks they can make the wave go faster. Inevitably a kid will say “I got this” and confidently move in to make a higher speed wave. He’ll (and isn’t it always a he?) try with more force or higher frequency and you will see a similar speed. Dude, I love this part. How can we change the medium? Oh, let’s stretch the Slinky more and BINGO! Faster wave. Bonus side-effect: you can use the same setup to show how increasing the frequency will decrease the wavelength of waves on the Slinky.

PS — I absolutely loved writing this 180 blog last year because it was fun to share something cool each day. This year, I struggled to get it going again. The biggest hurdle it turned out (thanks Jonathan) was remembering to take a photo or video daily. The other piece was a fear that everything I do this year will be a repeat of last year. I got over that by remembering it won’t be the same because I tweak stuff every year. Also, it could be fun comparing where I was this day last year. I appreciate all on Twitter who helped me think through this: @sterlace, @fnosches, @gfrblxt, @rawrdimus, @absvalteaching, @justinaion, and @_cuddlefish_.

Day 3: Slinky Waves

Friday, 15 August 2014

Forgot a picture today so I'll post something that made me smile on the first day of school.

Forgot a picture today so I’ll post something that made me smile on the first day of school.

I asked the kids today what a wave is. A number of them made a wiggling motion with their hand in front of their face. They all struggled for the right words but eventually got to “moves”, “energy”, and “repeating” which I figure isn’t a bad start.

Next we grabbed a giant slinky and went into the hall. I asked them to stretch the slinky about 3 meters across the floor then to make a transverse wave. “A what?” they said. They knew “transcontinental railroad”, so we went from there to get at the prefix trans-. They got it! Then they illustrated properties such as frequency and amplitude even though they didn’t have the vocab yet.

In between and after there was traditional note-taking — a part of class I’d like to minimize.