When I started teaching high school physics (during the Reagan Administration), I felt an obligation to "reinvent the wheel." I didn't blindly follow the sequence of chapters laid out by whatever textbook the school had. I was in charge of the curriculum! I wrote my own handouts, homework, tests, etc.
But what I turned out was a pretty true reflection of the introductory college courses I had most recently finished. Mostly the same topics. Mostly the same sequence. It wasn't so different from the textbook's sequence.
I had a whole unit on vectors. It followed my robust unit on "preliminaries" (scientific notation and so on). After vectors was the Month of Kinematics. One-dimensional, two-dimensional; graphical and algebraic. Ticker-tapes, falling bodies, the monkey gun... what's not to love.
The trees were losing their leaves before any mention of Newton was made in my class.
But I noticed a few things. My students never thrilled to the lessons of kinematics as I did. It's difficult, abstract material if you go into deeply. It took the human intellect about 2000 years to figure this stuff out. And we start the year in physics with it. And the year usually ran out before we got to how rainbows work or why the sky is blue.
I was thinking about slimming down my kinematics coverage when I saw Paul Hewitt refer to kinematics as a "black hole" in a Physics Teacher editorial.
Now I speed through motion. I cover it as much as I think it needs to be covered, then move on. (Sorry about the puns, but I'm a physics teacher; we breathe puns the way most people breathe air.) Newton's name will be uttered into air that could be 100F here in Sacramento. The leaves are still green in New England.
There are other ways to handle the problem of not getting to rainbows. The original PSSC program started the year with optics, an approach that galvanized a following even after PSSC abandoned it.
My point is to go easy on kinematics in particular and mechanics in general. First-year high school physics students don't need it to that depth.
The first year I went with the slimmed down kinematics, I held my breath and wondered which part of the sky would fall down. When June rolled around, I noticed that the whole sky was still up. And my students knew why it was blue.