0-100 Real Quick

One of the tricks of the trade I’ve stumbled across in making my class relatable for kids in an urban school is simply giving students some connections that are culturally relevant to them. One example of this is *ahem* one of my funniest jokes of the year.

It comes from this graph, an example of what lots of kids are inclined to do (before we’ve used those graphs to identify “initial values” over and over again). Rather than being scaled consistently from zero on both axes, this graph goes from zero to 100, “real quick.”

Admittedly, this isn’t funny unless you know the reference. For the uninitiated, here’s a link to the Drake song that I’m quoting here… clean version for the faint of heart.
http://youtu.be/cgLlmXl3qc4

What this song means for me as a teacher is I can write “0 to 80, real quick!” , etc on any graph axis that’s scaled incorrectly, and kids know exactly what I’m referring to. Here’s to making our graphs more useful than Drake ever would!

Energy Situations

I’ve been looking for quite some time for a sequence that I’m satisfied with for rolling out bar charts for more complicated situations. In my class, we spend a little time with just gravitational, kinetic, and thermal energy using the PhET Energy Skatepark, then step things up with more complicated situations. (Others may start with these more complicated situations, but I’ve noticed a need to work up to this with my students.)

I’ve finally arrived at an activity that I’m most satisfied with. This is very similar toy the Rex & Debbie Rice “Energy Stations” activity, but it takes place later in the unit, once students already have some practice making bar charts and talking about energy transfer. Think “wind up bunny” worksheet, but the key here is that kids are actually working with the stuff. We don’t take for granted that kids understand the idea behind a wind up toy, we use this as one example of many, and give them a chance to see first hand the connection between, say, a rubber band and a pull-back car.

The activity consists of three stations, with three pages of a worksheet. Students works through these three stations on one day, then whiteboard their work (with mistakes!) on the following day. Below shows the equipment I’m using (more on the iPhones in a later post).

At this point, students have some experience with energy discussions, and we’ve just looked at the PhET “Energy Forms and Changes” (http://phet.colorado.edu/en/simulation/energy-forms-and-changes) simulation with the girl riding a bike to power a lightbulb or heater to get an example of chemical energy. Since they have some facility with the energy transfer model already, they can actually discuss what’s going on in some detail.

The stations can be done in any order, and they all consist of a bar chart (with a system containing all objects defined in the dotted circle) AND a “description of energy transfer” with words. One of them features giant rubber bands that get shot against the ceiling. The second half of the worksheet shows “Moments A & B”, where the rubber band gets pulled backward.

Station 2 features a pull back car, very similar to the rubber bands, but horizontal. Moment B in the bar chart below becomes the first moment in a sequence where the car speeds up, then reaches a complete stop.

Station 3 features the classic “wind up bunny” question, updated to be a robot because these are the windup toys I found (http://www.amazon.com/Fun-Express-Wind-Up-Robots-Dozen/dp/B005NHT092). The second half of this station features the battery operated buggy – same idea but transferring chemical instead of stored elastic.

Here’s a Dropbox link to the actual worksheet I used, starting on page 6: https://www.dropbox.com/s/0ukll1ny9e8tv14/u2etm_packet2pdf.pdf?dl=0

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Foam Roller Coasters

I’ve been a little delinquent on my 180 posts this year, which is kind of a shame because things have been a huge improvement from last year. I figured I’d catch up on some important successes (and setbacks) to have them on the blog, in case their of some use to anyone else.

I was lucky to get a suggestion from a Chem teacher about these foam roller coasters for a marble… I hadn’t seen them before, but they’re unbelievably easy, cheap, and awesome. It’s super easy to make a roller coaster that works and is impressive, and everybody wants to get involved. We used the coasters as a bridge from “Skatepark Bar Charts” to actual situations involving real stuff. In a more advanced class, I could see asking students to use slow motion video to calculate the speed and kinetic energy of the marble at versions points.

I cut a bunch of foam pipe insulation in half, then taped four together length-wise. Since we didn’t have room in the room to make anything permanent-ish, students had to hold pieces of their coaster in place, which got even more hands involved. I taped one end to the end of a meter stick, and the only main rule was that the coaster had to start exactly 1m above its ending point. I gave points for loops, large hills, and for “landing in a cup”, and the winning group got some fun size candy bars. But mostly everyone loved just playing with the coaster.

Here’s a slow-mo video of a particularly amazing coaster, than gave us a chance to talk about where the energy was going: http://youtu.be/N5o2izY-y-w

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