Don't be shocked by AP Physics 1 questions. Justify your answer; Annotate your calculations.

Most of us who teach AP Physics courses are starting cumulative review for the exam.  I've written previously about sources for exam questions in the style of the new AP Physics 1 or 2 exams:  5 Steps to a 5, AP Central, the Big Amazing Resource at PGP-secure.  

Point is, if you haven't gotten the message yet, please hear it now:  Students who can calculate to get right answers, but who can not explain physics clearly in words with reference to facts and equations, shall not pass.  It used to be, on AP Physics B, that clever number crunchers could earn a 3 by knowing which equations to use in which situations.  Such folks will fail on AP Physics 1.  Unless, that is, they practice and get good at explaining in words WHY they chose the equations they did, WHY they chose the values for each variable, and what the fundamental principles are behind the relevant equations.

Ideally your students have been practicing their verbal justifications for all or much of the year.  If not, there's still time.  Assign the authentic practice exam questions, then make students correct everything they got wrong until you approve thoroughly of their solution.  

What if you need some free-response practice beyond the few resources linked above?  It's okay to use old AP Physics B questions or textbook questions, as long as you demand verbal explanations.  That's easy enough to do: in every question that says "Calculate," add the sentence to the end, "Annotate your calculation with a description of your approach."  Then hold students accountable for this description by marking the answer wrong and requiring a redo if there's not clear, verbal evidence of why they chose the relevant equation, and why they chose the values to use in the relevant equation.  Don't even look at whether the numerical answer is right; instead, pick one or two tricky aspects of the solution, and see if the student's explanation addressed those issues.  

In terms of multiple choice, there's no shortage of good questions available at the links above.  Physics B multiple choice from the last couple of released exams are also very good questions to use, as long as you eliminate the questions that are out of scope for the new course.  For all multiple choice questions, they become excellent verbal response practice if you simply add "justify your answer" to the end of them.

In my class the past week, each night's assignment has been three or four multiple choice questions that my students already saw on the trimester exam they took in March.  They are allowed to collaborate to determine the correct answer; but, they must justify that answer in clear, coherent prose.  This writing practice will serve my students well when they face the authentic AP Physics 1 exam on May 6.