Love the hook. “How old is Old Fred?” The visual is great too. Not a cartoon or some clip-art of a tree’s cross-section but the real deal. Really, I have very few complaints about this one. I’d just rather not see the problem abstracted to this degree (where it gives facts about growth rings and average thickness, etc.) just yet. Go with the conversation starters first. “How old?” It even gives you a good opener with “why are some growth rings larger than others?”
Fine hook. Just don’t tell them they need to know the radius (yet). Let them ask you for that information. The ideal visual would be video of a ferris wheel from a distance where you can watch the cart travel one full revolution.
Again, nice hook. Hooks plural, maybe. There are some nice things going on here. My sense of the problem is that the best hook would be “which horse is traveling fastest?” followed by video of a carousel in motion. The discussion that followed should draw out the tricky issue of defining “fast” with circular motion.
“Where did the lightning strike?” is nice. It’s the sort of hook that could use a satellite map from Google illustrating where Dimitri and Tara live. Also, a video illustrating the flash of the lightning followed by the sound of the thunder would be useful for students who don’t have a lot of prior experience with thunder storms.
Again, notice the concision of the hook. The illustration is nicely descriptive also. I wonder what we could add to the problem by developing the problem from an actual miniature golf hole. We could then show a video of someone completing the shot (or missing it).