Don't get into a holding pattern on kinematics

I'm sure you know of a hundred fantastic activities regarding motion.  I can bring up a bunch off the top of my head that I learned about just in the past couple of years:

* Roll a ball down a ramp or off a table, and try to hit a moving cart

* Launch a ball through three or four rings placed along the ball's parabolic path

* Just heard about from Michael Magnuson: Predict the launch angle such that a ball just barely kisses the ceiling.  (Hint: it won't work right the first time, because most likely students will not account for the size of the ball.)

* Kinematics Card Sorts from Kelly O'shea

And that's just the new stuff!  I still use the old standby 10 Hz dot machine to make motion diagrams, linearize a graph of drop height vs. time measured by the g-ball, quantitative demonstrations with a projectile launcher, graph matching, and more. We have so many fun, straightforward, well-tested activities in our arsenal.  Fantastic!  Unless...

Unless... unless we're still doing kinematics activities and review when Thanksgiving or Christmas hits.

Whether you're teaching AP physics or a conceptual class, it's important to move along.  There's more to physics than motion with constant acceleration.  Students who grasp the concepts quickly deserve to be challenged by force, momentum, energy, and some non-mechanics topics.  Those who struggle will, in fact, catch up through review in context.  Once you've established kinematics ideas well enough that half the class is rolling their eyes at yet another set of multiple representations of motion, well, it's time.  Another day isn't going to help.  Move along to something new.

Have faith.  It's happened hundreds of times for me, that I grit my teeth feeling like I'm leaving some well-meaning but slow students in my dust... and then months later, a kinematics problem comes up in a seemingly unrelated situation.  "Oh, yeah, I remember when this seemed hard.  I get it now," they'll say.  

Move along.  I spend only two to three weeks focused exclusively on constant-acceleration motion.  I save some of the most interesting activities for later in the year, when my students have developed stronger laboratory skills, or during the exam review when there's no pressure to discuss new content.  Since we move along so quickly this time of year, my April and May can be extraordinarily relaxed.