The spread is usually 40%/60% either way, and sometimes 30%/70% either way.
In reality, asking "How much X" usually isn't that helpful a question for your MCAT Prep. You've got to know as much as you possibly can. You could have only 4 questions with physics, but if you miss those 4 questions it could be difference between a 14 PS and an 11.
As always, a great point. The distribution differential from exam to exam is irrelevant given that there is no pattern. There's no way to know in advance how much you'll get, so you have to prepare by being ready for everything in both general chemistry and physics. And all questions count, so why not be prepared for everything?
From this point, I'm going to disagree with the overall opinion here about completing physics. Now let me start by saying it is
always better to have completed your pre-reqs before taking the MCAT, but it's not necessarily detrimental beyond belief if you don't finish everyone by the time you sit for the MCAT.
I point to UCI physics as a prime example. Students are advised at UCI to take physics their junior year, so many are faced with your exact dilemma. They are forced to choose between a delayed primary application (resulting from a July or August MCAT) or taking the MCAT without having the last quarter of physics.
Having taught the class in Irvine for several years (until a few years back), I found that most students could pick up the bare essentials of sound, optics, wave phenomenon, and EM with just a little extra teaching and a bunch of mnemonics. I would dare say that it was sometimes easier to teach them about the MCAT, because it didn't require
unteaching some impractical things they learn in physics classes. For instance, ray diagrams are great for school, but on the MCAT you don't have time to draw them (especially on a CBT). So, the plan is to do enough in advance of the test that you have a good visual of the different outcomes in your head. Once a student gets this visualization down and applies the variation on the thin lens equation we use, they can answer most any MCAT optics question in fifteen second, even the double lens questions.
So as weird as this sounds, not completing traditional college physics but instead learning
MCAT physics for that material can be an advantage. In the end, the average PS scores are the same for the people who completed physics as the people who didn't. I hear from the current Irvine physics teacher that the challenge is teaching people who took a full year of physics in a ten-week course.
The bottom line is that
if you can't complete your second semester of physics byt the time you take the MCAT, you can be just fine if you study from a question-answering perspective.
