My class is preparing for the second trimester exam. Even though I provide an equation sheet on the exam itself, I still think it important for everyone to know the relevant equations cold. Without such knowledge, students approach tests as a game of "find the equation with a Q in it." [See this post for some detailed analysis of how to use an equation sheet properly and improperly.]
My philosophy about memorizing equations relies heavily on, of all things, my seventh grade civics class. Nowadays I couldn't tell you offhand who the governor of Virginia is, or who sits on my local county board of supervisors.* But in 1985-86, I was the nearest thing to expert about Northern Kentucky and national politics. I knew who Paul Simon was before he ran for president. I knew that Kenton County's highest governmental position was called the "Judge-Executive." And I still know these things... As we drove through Louisville over the summer on the "Gene Snyder freeway," I began singing Congressman Snyder's radio jingle while I explained to Burrito Girl why his district encompassed BOTH northern Louisville AND suburban Cincinnati.*
*Or if Madison County, Virginia even has a board of supervisors.
* Burrito Girl is my wife and sidekick. As is so often true of my explanations, she didn't care.
Why did I, and do I still, know about civics? Because Keen Babbage taught middle school civics at my school in 1985. He didn't care that, even in pre-internet days, it was child's play to look up facts about local and national government. In his opinion, all educated citizens knew off the top of their heads the length of term for a US senator. And so, he made us learn these things.
Keen's crowning technique was the "4 minute drill," which I have adapted to physics. He placed a list of civics facts on his podium. He asked a question of each member of the class in turn; upon a correct response, the class earned a point, and he moved on to ask a new question of the next student. If that student didn't know the answer, he could say "pass," and the question passed to the next student.
Fast forward a quarter century. My class takes "fundamentals quizzes" regularly. But quizzes aren't always enough incentive to memorize facts; furthermore, even those who study diligently don't necessarily study effectively. I use the "4 minute drill" to ensure that everyone at least learns their equations.
About twice a week, I run a 4 minute drill using the equation sheet. I prompt something like "Force of friction;" the student has to say, "mu times normal force." I only allow each individual to pass twice per drill; if someone has to pass a third time, we sit there awkwardly until he either gets it right, or until the 4 minutes are over. We always run through the equations in the same order, so that we get farther and farther into the sheet over the course of a few weeks.
At the end of each drill, I write the class's score on the board. The sections of the same course compete with each other. Sure, I offer a wee bit of extra credit to the class with the highest score in the marking period, but they compete for pride.
If you'd like to try the 4-minute drill, get a copy of my 5 Steps to a 5 prep book. In an appendix, I list the verbal prompt I use for each equation on the AP physics equation sheets. You can easily run the drill by just reading each prompt in turn. And if you're not teaching AP, that's okay -- just pick the equations you've covered and skip the rest.