I'm regularly inundated with spam* offering to sell me question banks for AP Physics. And I'm regularly asked by physics teachers, "Should I buy these? My students want as much AP Physics review as possible." The answer is NO -- Don't waste your money.
* the electronic and paper version, but not the canned meat version
But why is it a waste to buy review materials? I can go on and on, as I'm sure those of you who know me could attest. Below are the major arguments.
Firstly, and most importantly: Why the obsession with extracurricular "exam review"? The AP Physics exam tests physics knowledge; presumably your class is teaching about physics all year long. The process of reviewing for in-class tests and exams is utterly equivalent to reviewing for the AP exam. I'm always amazed at how students beg for, and are willing to pay good money for, "SAT review" -- yet talk to those same students' English teachers, and find out how they haven't studied for a vocabulary quiz all year, and they didn't pay any kind of attention to the grammar and usage review that was intended to prepare them for the sentence completion section. I don't recommend feeding the exam review obsession, at least not until I can work out how to profit mightily from it. Just use every trick in your book to make your students take every problem set you assign seriously, and you'll be surprised how the need for "review" abates. Maybe if we made the students pay $10 per graded assignment, they'd realize that the best AP Physics exam review is their AP Physics class...
Secondly, why pay for what is widely available for free? Good physics questions, like pictures of naked people and cats, can be found online without difficulty.* While quality can vary widely, you can find enough AP-style practice questions to satisfy even the most compulsive student.
* Unless the Puritans at your school block all the hardcore physics sites.
Finally, let's talk about "quality." Writing good physics questions is HARD. Writing good physics questions that are in the style of the new AP Physics 1 and 2 exams is even harder. Some people I know to be outstanding physics teachers and physicists nevertheless have trouble creating clear questions at an appropriate difficulty level. And some of the worst sets of questions I've seen have been in commercially available AP prep books. Just because you're paying doesn't mean that you're getting useful questions, let alone better questions that are available for free.
So where do I get AP review questions for free, then? Start with the College Board's AP Central site. They've published half of an exam in the "Course Description," plus a smaller set of sample questions, plus a full practice test for those who have an AP Physics Course Audit account. I'm told that they will, eventually, publish a set of questions from last year's AP Physics B exam that would be appropriate for the new courses.
Next, go to "Pretty Good Physics -- secure." If you haven't signed up for an account with that site, do so right away. You can then access the Big Amazing Resource. Also, numerous teachers have posted their own activities and tests from which you can pull review exercises.
Use the 5 Steps to a 5: AP Physics 1 book, which includes a full practice test; next year's edition will include a second practice test. If you have a commercial textbook, look at some of their cumulative end-of-chapter exercises. (Nick Giordano is on an AP Physics development committee, and Eugenia Etkina's work has been used extensively in College Board publications. If you have a textbook by one of these authors, use questions from it as much as possible.)
For those who have been to my professional development, look through the CD I gave you. Don't look exclusively at the AP Physics tests; some questions from Conceptual Physics or Regents Physics are perfectly good for AP Physics 1 and 2. Some questions I used as problem sets or quizzes are good as test questions, or certainly as test review questions. I'll continue to update that CD. Come to one of my summer institutes in June, or to my free "Open Lab" in July, and everyone in attendance can share what they've created.
Or just pick a physics teacher you know and trust, and combine forces by sharing . Point is, in the era of crowdsourcing and the internet, there's no need whatsoever for you to spend any money just for a question bank. Don't buy a cow; milk is free.