Alert!

Hello, reader! If you intend to post a link to this blog on Twitter, be aware that for utterly mysterious reasons, Twitter thinks this blog is spam, and will prevent you from linking to it. Here's a workaround: change the .com in the address to .ca. I call it the "Maple Leaf Loophole." And thanks for sharing!

Tuesday, April 7, 2009

Real World Once Again Inconvenient

Here are three attempts to model "Will the Ball Hit the Can?" in Sketchpad:

Attempt 1: I try to make the grid scale match the given scale. (1 unit = 1 yard? Or close to it?) This requires the coefficient of the squared to term to be waaaay to small for clumsy freshman fingers.


Attempt #2: Make the scale very large. Now the leading coefficient is a little more friendly, but by comparison I have to make the constant coefficient slider way too short.


Attempt #3: Using a rectangular grid, so that the y axis is a relatively smaller scale than the x axis. Now all three coefficients are lengths I think the freshmen can handle. The catch? We can't even pretend this function means anything any more.
I'm going with #3, but it will bother me; I feel like I am perpetrating a ruse. On the other hand, I have learned way more about the behavior of the standard form of a parabola than I would have had I not bothered to try.
Feel free to email me if you want the sketchpad file to play with. It's 32MB.