Wednesday, November 26, 2014

Bungee Jump Physics Extravaganza!

I hate to overstate the case, but this activity is a whole lotta physics going on. Terms such as "Wow," and Bidenisms like "Literally over the top" come to mind.

In July, I jumped off a bridge. On purpose. In Africa.

A video was recorded.

Victoria Phyz Falls

Physics happened, and I was keen to exploit the event as an analytical assignment for my students. Because that's how I roll.

But such exploitation was not a trivial affair. I undertook the jump as a tourist about as far from home as I could be on the surface of the Earth. Deep in the midst of a month-long African wildlife photo safari detailed on The Treks of Phyz blog. Not as a physics teacher at a nearby amusement park loaded up with sensors and synchronized high-speed videography gear.

So hard data was limited. Easily measurable quantities on the captured video were limited. Quantitative information from the vendor proved… unreliable (See the "All the Facts" tab here).

What follows at the link below is a six-page student activity that could be assigned as homework or completed as a "video lab" in class. As always when working with a YouTube video, I recommend downloading ("ripping") the video first. As a Mac user, I then use QuickTime to trim and study the video.

A shorter YouTube Baird Bungee video can be found here.

The lesson engages issues including force and motion, Hooke's law, conservation of energy, and simple harmonic motion, among other things. There's qualitative analysis, verbal interpretation, graphing, direct measurement from video, and robust quantitative analysis.

In short—there is no "short": This thing is a beast.

I felt compelled to ask for a consult from Dan Burns, AP Physics C master teacher, YouTube sensation, general brainiac, and a maestro of mechanics. To suggest he is the Maxwell to my Faraday inflates my stature more than it does his. He was kind enough to give it a very thorough going-over. Many thanks, indeed, Dan!

Dan's analytical approach differed from mine, but we ended up with the same answers. And we both recognized some sticky issues incumbent in the quantitative analysis of such a data-poor problem.

But enough of my jibber-jabber. Allow me to present

Bungee Baird (PDF).

The answer key is available upon request to classroom instructors who send requests from their school email accounts. Kindly include "Bungee Baird Key" in your subject line.


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