For the last month, I have had this single image banging around in my head, hogging valuable CPU cycles. I couldn't find it anywhere else so I shot it myself. Click the photo for high quality. See the pilot for instructions.
BTW: The comments feature no fewer than two dozen lesson inspirations, at which point the questions become (I think) which lesson inspiration a) will sustain the most interesting math the longest? and b) which prompt can be summarized the most succinctly, the most viscerally? I think those are two of the most important metrics for evaluating these ideas.
Under that light, you have Ben Wildeboer: "Calculate time before impact with the ground." It's visceral. The student wonders first how she'll find that information in a static image. It seems impossible. The result is a page of physics function work.
Also: "How high was the ball when it was dropped?"
Or: "How long has it been in the air?"
My work for both of those questions:
The first answer is off by nearly a meter. That's just under 100% error.
BTW: A reader writes to let me know I blew the math here.
It seems that the work shown is using different reference points. At the top of the diagram the top part of the ball is used, and at the bottom of the diagram, the bottom part of the ball is used. I think the top of ball should be used for both or the bottom of ball; either of which would require knowing the diameter of the ball.
He's absolutely right, which would explain the 100% error.