My five favorite listings on 101questions this week:
- Soccer Ball Inflation, Nathan Kraft. My students are promiscuous with proportions, applying them to any situation where they have one known relationship and one unknown. That's my fault. A proportions unit ought to feature unproportional relationships right alongside the proportional and in similar quantities. So here's a good one from Nathan Kraft. If the small ball takes nine pumps to fill and it's half the size of the large ball, the large ball will take 18 pumps. Right?
- Swimming the River, Scott Farrar. Resultant vectors aren't always easy to visualize, which makes this invaluable. If I used this in a class, I'd probably cut it halfway so students could calculate the girl's odds of making it to the rock. Pairs well with Crosswind Landing.
- Tuba Echo, Nathan Kraft. So you have a guy honking away on a tuba, facing a wall that honks back. Gold
- Google Calc Error, Carl Malartre. For whatever reason these are pretty risky. Why is Carl at 80% with this while James McKee is stuck in Skipsville with Temperature Conversion?
- Please take a seat, Gulliver, Statler Hilton. My question: "How tall is the person who would sit there? How much would she weigh?"
Plus my own listings: