Day 2: High-Low Track (AP C)

The challenge lab in day 1 ended up being an example of a “High-Low Track.” I didn’t plan this, but the conduit that I used for the long track bent under its own weight, causing it to be steeper at the beginning and less steep at the end. A team that used the iPhone Compass App to measure angle found that the angle ranged from 6 degrees at the beginning to 2 degrees at the end. Even with this, students were able to determine the time relatively accurately (many groups within 10%). The Challenge Lab HW from day 1 asked students to write about assumptions they made when solving the problem, which lead to a discussion of the angle.

Today, I asked students to predict how this bow in the track would affect the time it would take to reach the end. My wife had the idea of using the hot-wheel track anchors to create these high-low tracks in my classroom. Here’s what it looked like:

Both tracks have the same total horizontal and vertical displacement. The bottom track is slightly longer than the top. Question #1 was “Which Hot Wheel car will reach the bottom first (if either)?” This lead to a great discussion, I wish I had taken pictures of the graphs that students drew to explain their reasoning. Most thought it would be a tie. Question #2 was “How will their speed at the bottom compare?” Most students correctly predicted the answer to the second question. We used the BeeSpi photogates and hot wheel anchors with photogate mount (my design) to measure the speeds. An average of 2.05 seconds for the top track, and 2.03 for the bottom.

2 thoughts on “Day 2: High-Low Track (AP C)

    1. Hi Marta! Sorry for the slow reply. I designed and 3D printed these anchors. If you have access to a 3D printer, I am happy to share the “.stl” files. This started as a project for my son’s room, and ended up being something I am using in class.

      Liked by 1 person

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