Day 110 – Two Bridges for TRU

Engineering Physics 12 – Two groups finished their bridges and wanted to be a part of the TRU bridge competition.  The top bridge was designed based on the group’s first attempt where they analyzed the failure mode(s) and reinforced those areas. I can get behind that kind of iteration design at this level.  The bottom design is known as being a strong structure, based on web searches.  There aren’t a lot of unknowns in long-running bridge competition that doesn’t change the design parameters…  In any event, they worked hard on the build and did their best to pay attention to small details.  We’ll see how they do.

Day 109- Printing a Pokeball

Math 11 – Here I’m trying to print a Pokeball that one of my Math 11 students modeled.  The first couple of tries at printing didn’t work too. I’m using Cura, and I found on Reddit that Cura allows the user to view the layers as they will print. Using this function and by modifying the support parameters, I was able to anticipate what changes I should make to get the sphere to print.  The supports aren’t needed for overhang, it’s needed to get enough material touching the buildplate so the part doesn’t slip while printing.  It worked.

Day 106 – Energy Transfer and Bar Charts

Physics 11 – Having sorted through pie charts, played with the Phet Energy Skateboard Park, and given a worked example, students were put into groups and each group was given a different situation to analyze in terms of energy transfer.  We then got together for whole class discussion and exhibition of worked solutions.

Some great observations by students

“Since there’s friction, shouldn’t some of the kinetic energy transfer to thermal energy?”

“On the left side you have 5 bars but on the right side you only have four.”

All in all, very good classes today.

Day 104 – Energy Skateboard Park

Physics 11 – After a two year hiatus, I returned to the Phet Energy Skateboard Park. This was the student’s first exposure to energy bar charts, after having spent a class on discussing energy as storage systems, and representing energy storage in pie charts.

The handout in the picture above has some leading questions for the kids to use while exploring the simulation. They didn’t hand in the worksheet. Instead, I used some plicker questions to check their understanding.

103 – Printing 3D Scaled Models

Math 11 – I’m slowly chipping away at printing models that the kids designed.  This student was pretty excited to try and print his Acropolis.  It worked out pretty good!  The idea with this project was to have students use 3D design software to practice visualizing and exploring 3d shapes. As well, I added small component of calculating scale to the assignment.

Day 102 – More Clamps

Engineering Physics – Students continue to work pretty well on their bridges.  I’ve brought in as many clamps as I can, but more clamps would be mo’ betta.  I’ve suggested that students go out and get their own packages of binder clips, which work very well.  I upgraded our glue to Lepage.  When I get the chance we will try to find its shear strength compared to the Staples glue.

Day 100 – TRU Bridge Contest

Engineering Physics – Students are now challenged with designing their own truss/bridge, which they will put in the Thompson Rivers University Bridge Contest.  Some students are experimenting with Bridge Designer software, others are working on their own designs based off of what we’ve already studied. Some groups are doing web searches for past TRU contest winners…

Day 99 – Scale Balance Metaphor

Math 8 – Students worked on scale balances, which seems to be a very good introduction to algebra and solving equations.  There’s the teacher candidate leading the charge.

In the photo below you can see how we’ve hung our curricular competency rubric on the wall. The hope is to make these skills visible and relevant as much as possible.

Day 98 – Breaking Bridges

Engineering Physics – Today we broke the bridges that students made. The previous attempt to break them was messy: I was hanging a bucket from the bridge where the bucket contained sand and hanging masses.  The buckets weren’t heavy enough so we then started stacking textbooks on top of the brides.  Once we got to 40 kg I called it off, as I didn’t want spilt sand and textbooks all over the place.

I built this bridge press in about 30 minutes, plus another hour for going out and buying the threaded rod.  The nuts gradually press the top beam down on the bridge and we monitor the bathroom scale for how much force is applied. Students used their phones to video record the scale because once the bridge breaks, the reading drops instantly.

There weren’t many broken popsicle sticks, almost all of the failures were with the glue. We used Staples washable white glue because it was cheap, but I wonder if the “washable” part makes the glue a lot weaker.