# Day 122: Phone Calls

We had a snow day a couple of days back, and conferences that were scheduled that night had to be canceled as well. We have been asked, as a result, to contact parents on our own time, and because my during school schedule is so crazy, I thought I’d hammer this out over spring break. I’m just about done, happy to be free for a real break soon!

# Day 121: Efficiency

Today (really last Friday) was the last day before spring break, so instead of moving into problem solving with Momentum per ‘the schedule,’ I decided that we could flesh out the difference between elastic and inelastic collisions via their mechanical energy efficiency. Students tested a variety of collisions and found that with our carts, magnet to magnet collisions had the best efficiency at around 85-90%. More data below.

# Day 120: Wrapping up the Momentum Paradigm Lab

Today we finished the Momentum Paradigm lab by deriving conservation of momentum starting with Newton’s Laws. I said 3 things (exact words);

1. Newton’s 2nd law

2. Newton’s 3rd law

3. Free Body diagrams

Go.

About half the class was able to derive conservation of momentum on their own, the other half with hints. It was pretty awesome for them to see that conservation of momentum can be found both empirically as well as theoretically. Quote of the day: “This stuff always blows my mind!”

# Day 119: Google docs, Doctopus, QR Codes, and Spanish

I had the rare privilege today of utilizing my position of technology integration specialists to hang out with my wife (who also keeps a 180 blog, though she’s a bit behind at the moment).  She for years has done an activity on commands where students make a set of directions and then another group has to follow them to find a prize. She has been frustrated that students can figure out where the prize is by just looking at the last couple of commands, and the German teacher tried using QR codes for each line of instructions so students can’t skip ahead. We took that a step further by using Doctopus to create shared documents that the students in a group and Alyssa could all access and edit, and they put their instructions and QR codes in that document for easy assessment. We learned very quickly how awesome this can be; the picture above, which may be hard to see, actually shows Alyssa giving some real-time feedback, as the group members worked on the activity.

Surprisingly, while the students went nuts with the chat feature, we found that within a couple of minutes they were using it very productively to have a conversation about what to do for the commands. It was somewhat artificial to force them to have the conversation there, but we wanted them to get a feel for how this could work even if they were not in the same room. Below is a great example of one of these conversations.

# Day 118: Building a Model

I took a lot of pictures today.

We are on day 2 of trying to find a model to describe car crashes. The picture above depicts formulas students developed to represent the relationship between initial and final velocities for two cars that crash together. At this point we have limited the situation based on the conditions below (we brainstormed this list after discussing the formulas above);

The arrow is the limitation we want to tackle next. I showed them a car crash where the cars bounce off each other, via magnets, and said go. Off they went. Below are lots of pictures of stuff they worked on as they tried to figure out the situation. Lots of spinning wheels today, which is good. Tomorrow they get a hint.

In the above picture, the student said, “I’m almost certain this has to be in the top…”

The picture above is a student explaining to her class how she reasoned out the equation first based on the ratios of the masses and how it should work out. That group’s data then supported her theoretically derived equation.

This equation is starting to get to something, though not a universal for all the collisions (I’m being vague since some of my students read this blog!) We’ll have that conversation tomorrow.
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# Day 117: Breaking the Model

Today we broke Energy. That is, we smashed a couple of cars together with velcro on them and found that energy isn’t so much useful for predicting things. However, there still seems to be a pattern…so we’ll investigate that the next couple of days. I’ll be writing more in detail on this on my more permanent blog in the next couple of days, I hope.

# Day 116: Conversations

Today we were whiteboarding, and before we actually started presenting two groups started discussion their answers. One group grabbed their board and brought it over so they could compare. I may turn this into a new whiteboarding mode in the future!

Below is the first picture I took, after which I made Matt look like he was actually engaged in the discussion.