Today we reviewed a bit for the quiz next class using a great card sort (click for link!) from Brian Frank (piecewise uniform motion)… the cards had a couple small errors (I think!) but they did great with it. It was a good review and the kids said “my brain is hurting” which is always a good thing! They had to match the written description, motion map, position graph, and velocity graph.
Next we started the Dueling Buggies Challenge. We are using this as a summative assessment for the constant velocity unit. They will need five representations of the collision – position graphs w/ equations, velocity graph w/ area calculation, coded pyret sim using next-x, algebraic Solving (since algebra classes just did systems of equations), and a motion map! Today we started brainstorming and collecting data….more next time!
Today was a busy day! Trying to get everything in before Thanksgiving break!
We started with the Dorothy and Toto discussion (I believe originally from Frank Noschese, at least that is where I remember first seeing it!) – and it produced quite a bit of fighting as usual! Some of them even took a meterstick and measuring tape to the screen! We then went through definitions of distance, displacement, avg. speed and avg. velocity. They did a little practice on this (wkst 4).
Then we did Worksheet 5 and they calculated the area under the curve on the velocity graph… I ended up having to lead this more than I would usually like, but I HAD to just get this handled before the break. (They have to do the backside for HW.) It was pretty cool that they pretty easily recognized delta-t * velocity as delta-x which was the area.
I gave them some practice to do for homework and we will have a quiz when we get back, and then do Dueling Buggies… we skipped worksheet 3 and did the other stuff first, and we will circle back and make Dueling Buggies into a sort of summative project. The kids just did systems of equations in algebra so we will add that in too!
Today we sort of finished out our next-x function… I am still not 100% clear on why we need to write this as a 2 argument function, other than to plant the seeds for acceleration when “velocity” becomes “current-velocity”… maybe that is the reason.
We started by having them finish the motion map scenarios, and then checking them with the code we wrote last time… drawing these motion maps even made me think for a minute! It is pretty cool to be able to have something to check your thinking… I wish we had time to WB these too but we have to move…. I had to let that go. But I think they got it.
Then I told them we wanted to make a new generic next-x function, after we looked at runners 1 and 2 and saw their functions are really kind of the same…The meeting we had earlier this week with the summer cohort really helped me! I could not understand how pyret had ONE function (the new generic next-x) and still drew 2 runners… when we could see the background code and I could understand what the sim was calling for, I saw it better and was able to explain it to the kids.
They struggling pretty mightly with writing this function – especially my block 4 who REALLY couldn’t see it and were writing all kinds of crap like next-x is current-x + velocity…. BUT after much teeth-gnashing, we got there! Blocks 1 and 2 figured it out a bit more quickly, but block 4 got there by the end, and WOW the kids were pretty excited when they got it figured out. In 1 and 2 I had a little more time, so I had groups who had it right walk around to groups that still had mistakes to help them out. This was super fun and we felt like a real big community of learners, it was very nice!
And how brilliant do these kids look when we have wall whiteboard covered in this!?!? I am pretty impressed with them!
We then coded it, and changed delta-t to 1/20 sec from 1 sec… and it was good for them to have to make the calculations again. I was just thinking too, how sad for kids who learn constant velocity motion in like a day, as one random equation like speed = distance/time or something… there is so much richness here to explore!
We started class by jotting down some rules about drawing position and velocity graphs, then it was time for 2 runner pyret! They did Worksheet 3, fairly easily got through figuring out where the runners meet, and then wrote design recipes for two next-x functions, one for each runner. This was pretty smooth, and most of them remembered decently how to write the functions. Then they programmed them, and used them to test their prediction from page 1.
One note: I had jotted down from the summer that I didn’t like that the worksheet has black/gray motion maps in different places on the worksheet and the sim… also the scales were different and the dot-rate. It may have been ok as is, but I felt more comfortable changing the example on the front page to look like the sim… maybe there was a reason that the worksheet was 2 second tick and sim is 1 second tick… Mot of my kids are ok, but I do have some pretty lost, so I decided to just take that out of the equation. I also don’t like that they are called v1-initial instead of just v1… I guess it turned out ok, but I may change it next year now that I know how.
Today we lost about 30 minutes of class time, so I ended up spending the whole time reviewing some things we had learned about position and velocity graphs. I stole some graph images from Joe Cosette (https://passionatelycurioussci.weebly.com/… he has lots of great stuff BTW)… and we just practiced making some graphs. We did not get to start the 2 object runners, but I didn’t want to push it… Overall, this went fairly well!
Today we learned how to draw velocity graphs! We used the motion detectors and it went fairly smoothly. They seemed to be able to pick out the “good” parts of the graph pretty easily.
After they finished I had them make a quick WB showing how you see fast/slow and +/- on each type of graph. I think they got this very quickly and seemed to really understand it! I loved how after they made the WB and I said let’s discuss, they just circled up and got ready to talk! 🙂
Time for the old throwback Modeling worksheet: 2 bicycles! We worked on this in groups and I asked them to create another representation (thanks Melissa). They did motion maps, tables, pyret functions, and equations.
As they were working it became pretty clear that they thought the bikes would be moving in an “X” shape – this was more prevalent than in previous years… maybe because we didn’t really graph the buggy lab like in the past. So I started telling them to get up and walk it, and whenever they would walk in an “X” I would say NOPE. And they were getting frustrated (in a good way) and like arguing between groups about how they thought it should be. It was very productive! Eventually, some folks figured it out and then I had them model for the class. It was good to have them walk it and get rid of the “X”!
Then I tried (again a la Mellissa) to have them WB the front or back. Then I put all the fronts together and the backs together to compare. Then paired a front and a back to discuss. I was listening and they seemed mostly to get the big ideas, but I was not able to really pick apart the language and stuff as in the past when we WB all together… so we will see how that shakes out as we move forward.
Day 28 we got back to our whiteboards with the post-it notes. After they created the multiple delta-t’s markings, we rotated the boards and moved the post-its to the corresponding times. This was a bit more challenging than I thought, but we got it done.
Next we worked on finding the slope… I liked this method because I made them find it in multiple places, and they could see that it was the same no matter which 2 points were selected. The kids said lots of great things about “rate of change” being the same… I credit a lot of this ease of finding slope to our algebra teachers and that we are doing this later in the year than usual.
We then worked on finding the equation of the line – most wanted to write y = 2x + 1, but I said I want an equation about THIS BUGGY, not any random line. They struggled a bit and had good discussions… I then wrote the next-x function on the board and asked them if it was telling the same story as the graph. This sparked some really interesting conversations!
Eventually we settled on the equation of the line. Then we plotted some data to practice position graphs and writing the equations.
I was out of town, so they took the quiz while I was gone. One side was about the next-x function – and showing the different delta-t’s and delta-x’s. The other side was motion maps. For the most part, these all went well!
I didn’t have anything else for them to do since we had not gotten far enough on position graphs… so I had them gather and make Jamboards of “The Model so Far”. I was pretty impressed with these, and they did them without me there at all!
Modeling in 203 