I enjoyed writing my solutions to the 2016 AP Physics 1 free response questions. You can find the questions linked via the official College Board exam site, here.

As always, I guarantee that I've earned a 5, but not that I get every detail right.

But more importantly, as we move farther in time from Physics B, remember that AP Physics 1 exam questions ask for explanations and creative descriptions. Your answers may not be the same as my answers, yet may be fully correct. Conversely, just because you cite the same general physics principles as I do doesn't mean you've earned full credit. The quality of the explanation is the key.

My solutions can be found via this link, at PGP-secure. This is a wiki for physics teachers only. If you are a teacher but don't have access yet, follow the instructions at the linked page; you should be approved in a few days. If you're not a teacher, get your teacher to join!

GCJ

Agreed with almost everything you had with one exception. on 3(di) wouldn't the graph need to have a y-intercept of 0 since M=0 would indicate an average v=0? The data trend does not seem to show this. Also, wouldn't doubling M also double average v? The data doesn't show this either. Otherwise I was in agreement. Thanks for posting these.

ReplyDeleteYou are right! Oops. I looked too simply. Neither the slope nor the intercept matches the equation, though the linear relationship does. Thanks!

DeleteGreg

Can you post publicly for students to access?

ReplyDeleteSorry, I can't. College Board materials aren't allowed to be shared via unprotected websites. I can only share directly with teachers and with my own personal students.

ReplyDeleteGreg, Many thanks for the solutions. I sat down this morning with a couple of my students and we worked through the problems. Then we checked our work against yours and were pleased that we had done very well except for #3. Within minutes we had the corrections :)

ReplyDeleteI used your "5 Steps to a 5" over the last month to prep for the exam. It went very well and it was obvious that the text and methods are beneficial. We will be using your "5 steps to a 5" next year! Thanks for all your hard work!

For 1(b), can you cancel the M and simplify? I realize the question says to answer in terms of M, theta, etc., but then also says "as appropriate." Thoughts?

ReplyDeleteOn 1(b), can you cancel the M and simplify? I realize the question says to answer in terms of M, theta, etc., but then follows that with "as appropriate." Thoughts?

ReplyDeleteMatthew, you are of course right... But the simplest form of the answer isn't important. Your simplification is right. Mine is also right. As long as you have solved for the correct variable, and as long as no "illegal" variables are included, you are fine.

ReplyDeleteMy students commented that the exam had very little rotational motion beyond the FRQ with rotational kinetic energy. Is there an effort by test writers to match up the percentage of objectives on a topic with the percentage of questions on the exam? We had spent a lot of our review time on torque and conservation of angular momentum, so students were surprised that the exam focused on linear concepts and didn't seem to have a balance. Do you have any insights/advice on this?

ReplyDeleteSara, my understanding is that what we think of as "topic areas" are virtually irrelevant to the distribution of questions on the exam. Questions are distributed by combination of "Big Idea" and "Science Practice."

ReplyDeleteFor our purposes, that means a problem relating torque to angular acceleration is EXACTLY EQUIVALENT to a problem relating force to linear acceleration. Conservation of angular and linear momentum are equivalent in the development committee's eyes, as long as the questions use the same science practices.

Now, I'm sure there are discussions among the committee about balancing linear and rotational concepts a wee bit. But I'm not privy to those conversations. In terms of the goals of test writing, an exam could in principle be entirely linear, or entirely rotational, and still be considered a valid exam.

As always, I take the most inference from actual, authentic, released items. And in the first two years of the exam, those released items are more heavily linear than rotational.

Now, Sara, we haven't seen the multiple choice. I'm personally skeptical that there weren't at least a couple of rotational problems on the multiple choice. I think students see what they want to see: they wanted a torque or angular momentum problem, didn't get it on the free response, so likely ignored or forgot that it showed up in the multiple choice. That said, unlike the old Physics B percentage distribution of topics, it's quite possible that torque and angular momentum were in fact a negligible portion of the AP 1 exam.

This year. :-)

GCJ

Maybe I'm crazy, but I can't get my head around in 1b)f = uFgsin(theta), why is it not uFn, where Fn = Fgy = Fgcos(theta)

ReplyDeleteWas the raw score translation for physics 1 2016 published?

ReplyDeleteHey Mr. Jacobs! I thoroughly enjoy your posts and find a lot of value in your resources. I have a question about FRQ scoring. I use modeling instruction in my classroom so a few vocabulary terms that I use are different from a traditional physics course. For example, my students would call the normal force a flex force and the net force an unbalanced force. I do teach them both terms but I find they usually prefer flex and unbalanced force to Fnet and Fn, will these cause a problem for graders reading their FRQ's? Thanks for your time!

ReplyDeleteElizabeth, answered in the post of Oct 26 2016. Thanks for the question!

ReplyDeleteNice solution!

ReplyDeleteHey Mr. Jacobs

ReplyDeleteCan I post on my moodle page your facts sheet in a modified version? (different order, additions, deletions and such)?

Nili, yes, you may modify the fact sheet and use it as you wish... please (a) credit me somewhere, something like "based on work by Greg Jacobs" and (b) indicate that you've made modifications, something like "and modified by Nili Sadovnik". Thanks!

ReplyDeleteGCJ