Impromptu Project: Renting Students Water Bottles

All day today I've been building rockets with my physics students. We're going to use them to as an excuse to run some calculations about acceleration with real data, and also I get to work in some rather tangential physics-related topics: center of gravity, center of drag, gyroscopic motion (rifling), as well as Newton's 3rd Law. It felt awfully like a nonsequitor though to jump in to these other topics while acceleration was the supposed to be the purpose. I could do rockets with Newton's 3rd Law, but really... by the time I get to Newton's 3rd law launching rockets outdoors is unpleasantly chill.

I didn't think 8th period would be much different, but a dialogue from yesterday came up at the beginning of class. We make these rockets out of water bottles from the recycling, and yesterday it came up how plastics have BPA and it's so silly that people buy these bottles over and over, when they could just bring their own.

So today, the kids came up with the idea to rent BPA-free Nalgenes or Kleen Kanteens in the cafeteria to students who forgot to bring bottles of their own, and it'd be cheaper than buying water. Yay! I said, "To heck with the rockets! This is way more interesting". So we spent the entire class hashing out a mission statement, we called Kleen Kanteen and they said they could get us a 30% discount on a <100 shipment of bottles (amount tbd), and we spoke with Debbie the kitchen lady about what we should consider before we go to Betty the head kitchen lady.

This. Is. Awesome.

I'm so excited to see how it all turns out. We really need Betty to be on board, because I do NOT want to wash water bottles after school :( :P

To do this I think we need to show her that this system will pay for itself and how soon that will be, factoring in: extra washing time/man power, soap, initial cost of bottles, and proposed cost of renting a bottle, approximation on how much this would reduce her Dasani water profits.

Meanwhile we should also calculate the increase of local water consumption, ultimately going back to the local utility and staying in Montpelier. I think the students would like to do a taste test of the drinking fountains in the school as compared to Dasani water. My hypothesis: no one will be able to tell the difference when they're all at room temperature.



This is all great. Yummy. Wonderful.
However, at the end of the day I am left feeling a little silly... how will I justify that they are learning physics by doing this?

I could call it a gigantic Fermi problem that got out of control. I could call it chemistry - oh wait, that doesn't work. I could say it's energy. I could say it's unit analysis. Or better yet: Vital Results! haha :) As long as they sufficiently learn about acceleration in the same amount of time as the other students I will be happy. Suggestions welcome... :)