I am really loving linking interaction diagrams, free body diagrams, and equations in Balanced Forces. Tomorrow I will have the students do this same problem except treating both blocks together as a single system.
I’ve seen and played with Edmodo before. What I didn’t realize what that, unlike many other LMS’s, the iPad app is fully functional. We have a number of iPad cart pilots that I am helping with in my role as a tech integration specialist, and one of the huge problems has been ways to get work produced by students on apps into a teacher’s hands, particularly because the iPads are not 1:1 (as many as 7 students use one iPad on a given day, so they cannot have one student’s login information as would normally happen with an individual iPad). Edmodo may be our solution, as students can upload, at the very least, items from the photo roll and Gdocs to posted assignments.
My 2.5 year old son valiantly tried (for the first and last time) to escape from his crib on Saturday and broke his arm, and it had to get set today. Thus I was not at school. Above is the exact copy of the sub notes for today. I love how many times I was able to put “They will know what to do” and mean it. I am exited for tomorrow to see how they did!
Today we whiteboarded the balanced forces WS 1. The problem above spurred a conversation about how we know the forces balance (they must, since the velocity is constant, right?), at which point I prompted the group to draw the dotted lines (A new term, components!), label them, and then use them to write an equation. I found this a thrilling way to hint at Newton’s 2nd law (and to represent Newton’s first). Additionally, both classes got into a great discussion about a block being pulled across a table with friction and whether tension should be bigger than friction, both with CV and not CV. 7th hour didn’t resolve it when the bell rang, we’ll be coming back to that tomorrow!
I generally have groups of three, with a few groups of two. They work together through a unit, then I switch the groups. I had the groups members number 1 through 3. I had them work through the problem (whiteboarding yesterday’s Modified Atwoods situation, where we drew Interaction Diagrams and Free Body Diagrams for each of the three sections of motion; at rest at the beginning moving with the rope pulling the cart, then moving after the weight has hit the ground so that the rope is not pulling (much) anymore). Anyway, after they completed the problem I had the 1’s move to the right and the 2’s move to the left, with the 3’s staying put. Thus there was an original member of the group, who ended up essentially trying to defend what they had done, with two new group members who then added their perceptions to that particular board. They made changes to the board in a different color than the original board. Then I nominated a group (usually one that had a particularly interesting discussion going on) to present, and we came to consensus that way on the first section (at rest). This was mostly to make sure that everyone was on the same page and we didn’t have any rouge groups.
I had them move again (again only the 1s and 2s) and then simply modify what was already there to now represent the second section of the motion. Then they moved again, edited again, and a group presented. Repeat one more time for the last section.
In Kelly’s and Sophie’s version all the students end up working on work that is not their own; in mine I had students who stayed rooted to their original work. I see value in both and plan on trying their version next time around to see what I think. I also liked that this sped up the whiteboarding process; I don’t think we needed to have a whiteboard meeting for each of these three scenarios. We were able to get through this and move on to start whiteboarding the next worksheet in a 45 minute period.
Today we finished up the process of discovering Newton’s First Law through interaction diagrams and free body diagrams. We then took velocity vs time data of a modified Atwood’s Machine, where the cart is first at rest, then being pulled by the rope, then coasting when the mass hits the ground. Tomorrow we will whiteboard interaction diagrams and free body diagrams for these three sections of the motion. Thanks to Matt Harding for the idea to do this!
Today we jumped into drawing Interaction Diagrams and Free Body Diagrams. Tomorrow a pattern emerges.
Today was the first day of Balanced Forces, and I start it with a slightly modified version of what Kelly does using the pictured Kick Dis. The one thing I do differently is that I prefer to go through all my snapshots (I do 6: Puck at rest air off, rest air on, gliding air on, gliding air off, pulled with rope, moving in circle because of rope) by first looking at the type of motion for each, then doing all the interaction diagrams, then doing all the free body diagrams, and finally looking at balanced vs. unbalanced for each one. I do this because this is students introduction to both IDs and FBDs, and I like focusing first on one then the other on this day.
Under the Kick Dis is a Force Plate that came in the mail today, very exciting! I just wish we had enough money to purchase two of them so we could use them for Newton’s 3rd law demonstrations, but we’ll have to find that money another time.
Yesterday was a staff development day. Our principal wanted us to remember what it is like to be a kid, so for the afternoon we all got a schedule. It was a bit humbling to go to four different ‘classes’ and try to remember everything, definitely a good experience.
Today I gave students time to sift through their data and prepare to write their first lab report. It is really nice having laptops for groups in class, especially because the 10 I have combined with 16 in the mini-‘wing’ labs means I easily have enough for all my students in the even that each student needs a computer.
I also wanted to comment on the value of lab reports. There was a conversation on Twitter questioning their value this fall, but I see lots of value in reports. First of all, I think that technical writing skills are important and will be useful for many students later on. Second, I really like that lab reports hit on skills that are difficult to assess otherwise; data interpretation, synthesis, and logical argument leading to a particular conclusion (I even use the word ‘thesis’ since they have been hammered with that term for years; our district actually does a pretty good of having students write across the curriculum). I think that reading a lab report helps me get into the heads of my students easier, as they have to explain reasoning behind their choices.
But oh, the grading!
It’ll probably take me 6+ hours of grading to get through my 35 honors students’ reports, and this is essentially a rough draft; they will revise and turn back in. I think it’s worth it though.