Choosing Between Physics B and C Exams

[cryptoguy]

My school offers an AP Physics B class, but it also let's us take the Phys C M & EM exam. I am very interested in physics and plan to go into a field that combines physics and computers. The choice I am faced with now is which exam(s) to take.

I am definitely taking the B exam, and the Mechanics portion of the C exam. The problem I have is with the EM portion whose review book initially looked like it was written in Greek.

My problem is that I think I understand theory, but mathematically I am daunted by the monsterous integrals of Gauss, Ampere etc; I've taken AP Calc BC.

Does anyone have any suggestions/recommendations/advice on the matter?

Thank you.

 

[ice109]

there's no difference between the c class and b class. i highly doubt you'll have to do any real integrals.

 

[awvvu]

No, that's definitely wrong; I'm pretty sure you wouldn't be able to do well at all on either the mechanics or E&M exams for physics C from physics B knowledge without self-study. The calculus used by physics C is pretty simple, but it'll cover everything in much more depth. Take a look at the course descriptions:

http://www.collegeboard.com/prod_downloads/ap/students/physics/ap-cd-physics-0708.pdf

 

[Tickitata]

I was in your situation, as my school didn't offer a physics C class. I ended up taking both sections of the C exam, but not the B

although I was good at all the B material for E&M, I got completely rocked on the test. 4 on mechanics, 2 on EM.

It'll definitely take a lot of self study, but even if you pass it, I think you really should take the course in college. It's much more beneficial.

 

[ice109]

No, that's definitely wrong; I'm pretty sure you wouldn't be able to do well at all on either the mechanics or E&M exams for physics C from physics B knowledge without self-study. The calculus used by physics C is pretty simple, but it'll cover everything in much more depth. Take a look at the course descriptions:

http://www.collegeboard.com/prod_downloads/ap/students/physics/ap-cd-physics-0708.pdf

have you taken the classes? i stand by what i said.

edit

i even looked at the sample tests. 1 derivative each.

 

[awvvu]

have you taken the classes? i stand by what i said.

edit

i even looked at the sample tests. 1 derivative each.

Yeah, like I said, the calculus isn't hard. It's just a difference in the topics covered. See page 18 of that PDF (content outline).

For example, how is a physics B student supposed to answer the problems involving rotational dynamics? See the sample multiple choice questions 8 and 9 and the free-response question 3.

I'm taking physics C currently, and the physics B questions are a lot easier (although it covers more in breadth).

It's going to require some self-study if you're taking a physics B class that doesn't cover this extra material.

 

[ice109]

hmm we had rotational dynamics on our B test. w/e

 

[!Mi Vida!]

Strange...

there's no difference between the c class and b class. i highly doubt you'll have to do any real integrals.

From your posts it seems you have taken the Physics C and B exams so you must know. But it just seems strange to me that College Board will create two tests with exactly the same material. Now I haven't taken either test but I plan to take both C tests come spring so take what I say with a grain of salt. Right now I'm using Princeton Review 2006-2007 edition to prepare. The book is for both the B and C tests and separates the material when necessary. I've gone through the mechanics and most of the E&M sections and from what I see, wherever there is a section separating B from C material the seperating factor is usually calculus. For the mechanics section it's usually simple derivatives (as you said) but for E&M it's usually an integral if not more. For example a problem that I looked at the other night was concerned with finding the electric field of a charge distribution. The solution set up a differential charge element and related it to a differential electric field element with geometry. Next an integral was set up and evaluated to find the field. And just in case Princeton Review has no idea what actually is on the AP exam, I went to the College Board website to make sure I wasn't wasting my time evaluating integrals I'll never have to evaluate on test day.

Here's the link http://apcentral.collegeboard.com/apc/members/repository/ap05_phys_objectives_45859.pdf" but you need an account to view the pdf so I'll just copy and paste a few things

..Students should knowhow to deal with situations in which acceleration is a specified function of velocity and time so they can write an appropriate differential equation and solve it for v(t) by separation of variables, incorporating correctly the initial value of v..

Forces and potential energy:Students should understand potential energy so they can: 3.)Calculate the magnitude and direction of a one-dimensional force when given the potential energy function U(x) for the force

a) Students should understand the technique for finding center of mass, so they can:(3) Use integration to find the center of mass of a thin rod of non-uniform density

b) Students should understand the concept of electric potential, so they can:(7) Use integration to determine electric potential difference between two points on a line, given electric field strength as a function of position along that line.

3. Maxwell’s equations
Students should be familiar with Maxwell’s equations so they can associate each equation with its implications.

...and as an example of the degree of familiarity suggested, here's the level of understanding for Gauss's law

b) Students should understand Gauss’s Law, so they can:
(1) State the law in integral form, and apply it qualitatively to relate flux and electric charge for a specified surface.

(2) Apply the law, along with symmetry arguments, to determine the electric field for a planar, spherical, or cylindrically symmetric charge distribution.

(3) Apply the law to determine the charge density or total charge on a surface in terms of the electric field near the surface.

My point in using these examples is that the B and C exams (as defined by College Board) are not the same exam.

To the OP: If you want to major in physics, it would be a great I dea to start learning some college physics now aka Physics C. Mathematically the E&M portion for the C exam is quite daunting compared to the B exam but with your knowledge of BC calculus you should be well prepared for self study. As a preparation aid I recommend Princeton Review because it gives a very good review of the material and gives you difficult problems that help you develop familiarity with the subject.

 

[ice109]

to me the slight bit of calculus in the c versus the b test does not imply a difference.

 

[CPL.Luke]

odd the test I took required quite a bit of calculus, with seveeral tough short answer questions liker calculating the power running through a loop of wire which was oscillating in a (time dependent) magnetic field.

and the finding the charge on a capacitor as a function of time.