If you are going into engineering and want college credit, take AP Physics C. Look up the requirements for graduation yourself and you’ll see that calculus based physics for engineering. You probably won’t get credit toward graduation for AP Physics 1 or 2 in engineering because you can’t get credit for both algebra based and calculus based and you must take calculus based physics as a prerequisite for the follow on courses.
The level of calculus in the AP Physics C test is not deep. You merely need to know enough to be able to understand what differentials and surface integrals mean. But it’s necessary to see the physics in the calculus based framework to proceed.
Would anybody happen to know the extent at which RC circuits are tested? There is a fairly annoying differential equation used to find the charge of a charging capacitor over time (and with, derived formulas for current / voltage of charging capacitor and formulas for charge / current of discharge capacitor) that is not on the formula sheet.
According to the framework, C) 3) a) 4) “Calculate the voltage or stored charge, under steady-state conditions, for
a capacitor connected to a circuit consisting of a battery and resistors.”
C) 3) b)
"Students should understand the discharging or charging of a capacitor through a resistor, so they can:
Calculate and interpret the time constant of the circuit .
Sketch or identify graphs of stored charge or voltage for the capacitor, or of current or voltage for the resistor, and indicate on the graph the significance of the time constant .
Write expressions to describe the time dependence of the stored charge or voltage for the capacitor, or of the current or voltage for the resistor
Analyze the behavior of circuits containing several capacitors and resistors, including analyzing or sketching graphs that correctly indicate how voltages and currents vary with time"
Time constant = RC
If charging from initially no charge, at t=RC, capacitor has 63% of its final charge. On the charge vs time graph, charging is an increasing, concave down curve with initial value of 0 and an upper asymptote q=C*emf. On the current vs time graph, current is a decreasing, concave up curve with initial value of emf/R and a lower asymptote I=0. If discharging from initially full charge, at t=RC, capacitor lost 63% of its initial charge. The greater the time constant RC, the slower it takes to charge or discharge.
Isn’t this the same thing as C) 3) a) 4), or are the equations just manipulated in terms of t instead of q, I, or V? Or is it something else entirely?
My textbook never discussed multiple capacitors or resistors. I’m assuming that, with multiple resistors or capacitors, time constant would increase which would mean it would take longer to charge or discharge the capacitor. On the graph, multiple capacitors and resistors would make the graphs change more slowly, leading to less steeper curves.
Could someone add on to this and tell me whether the q=C*emf(1-e^(-t/RC)) and respective derivation equations are necessary for the AP?
Thinking about taking AP Physics C or AP Physics 1 next year(senior year if that matters) and I had a few questions. I have heard that the teacher at my school is pretty good, but the course is still difficult. I was thinking of taking this class concurrently with BC Calculus(which is extremely difficult at my school due to the teacher’s rigor to prepare for the actual exam, I’ve had him before and I like him a lot tho). I took Honors Conceptual Physics freshmen year and I had an awful teacher, so I basically had to teach my self physics and got an A, but it was also a topic I enjoyed. I plan on doing electrical engineering, so this course would definitely be helpful. I know it’s not a prerequisite, but should I take AP Physics 1 before university physics?
Hi. I’m currently a junior and it will soon be the time to choose courses in my school. I still haven’t decided whether I should take AP Physics 1 or AP Physics C (possibly both exams) for my Senior year.
I have already taken a physics course in my high school (NOT AP Physics 1) and so I already have knowledge on forces (Newtonian), work, energy and circular motion. Also, I am taking AP Chemistry and have an A in that class. Someone told that taking AP Chem provides an advantage on understanding concepts in E&M. (Is that true?)
Next year, I will be taking AP Calculus BC (no doubt), which just further proves my love for math.
But I have heard AP Physics C is a really challenging course and it may require more knowledge on Physics, which has made me doubt whether or not I should take it
Hence, I would love any advice that might help me with my decision. Thanks in advance.
The choice between AP 1 and AP C/mech/em depends on a few things. Calculus is required for APC, but it’s not that much calculus. If you are taking Calc BC, your math is more than adequate for AP Phys.
If you are going into engineering or physics, only APC “counts”. Take that.
If you are going into liberal arts: AP 1 will count.
Other majors: Depends. Look at the specific physics required for your major, and then see if AP 1 gives credit for that course. If it does not, look if AP C does.
But perhaps you can look and compare number of hours of credit granted. AP 1 is the equivalent of a 1 semester long course-- but usually more than 3 hours. AP C mech/em are two semesters of physics also often more than 3 hours. So APC does cover “more physics” than AP Phys 1 because it covers two semesters worth rather than 1.
The topics you mentioned are all “mechanics”. Did you do any electro-statics, circuits or magnetism in highschool? If not, I would suggest a simple conceptual Mooc that discusses some of that. (Actually, we are discussing AP choices at my blog right now. You can read here:
AP Chem will not significantly help you with AP Phys C EM. You probably already know electrons are negative and protons are positive and opposite attract. (Though if you don’t you’ll learn that in AP Chem.) AP Chem does include some EM concepts-- but those are the ones that would help with AP Phys 2-- which discusses particle physics, waves, photons ans stuff like that. That’s not in AP Phys C which is geared to get people ready to start their circuits, power generation classes. Particle physics is deferred to the 3rd engineering/physics phys class.
Could someone add on to this and tell me whether the q=Cemf(1-e^(-t/RC)) and respective derivation equations are necessary for the AP? *
The derivation is unlikely to be required on any AP Phys test. HOWEVER, you need to know how to find “C” for a particular application.
My textbook never discussed multiple capacitors or resistors. Potentially, there could be a problem that has multiple resistors or capacitors inside an RC circuit – like two resistors in series in the loop with the capacitor and/or two in parallel. None of those horrifying mixed parallel and resistance tough. You need to be aware that “R” in tau=RC is the equivalent resistance in the loop with the relevant capacitor. So series will increase R and increase tau. Parallel will decrease R and decrease tau.
Isn’t this the same thing as C) 3) a) 4), or are the equations just manipulated in terms of t instead of q, I, or V? Or is it something else entirely?
Do you mean is the solution for the steady state the same as the solution for the time dependent behavior? No. The steady state as as time -> infinity. (You probably know how to do this if you are talking about this at all. )
I honestly have no clue what to call what we’re covering. We just finished up some stuff about finding the electric field for various 3D shapes and some stuff about electric potential, but I don’t know what my class will cover next.
Yeah, we just wrapped up with electrostatics, electric field, potential, capacitance, and dc circuits. Idk if our pace is fairly medium or slow, but it feels slow tbh. Seems like there’s a lot more to cover.
I took AP Mechanics last year and I am taking AP E&M this year. Anyone have any book recommendations that focus more on the E&M side of Physics C? Barron’s and Princeton are nice but a last resort because they have a lot of unnecessary Mech in them.
Hey guys. I have the PR book 20017 edition but I have heard mixed things about the Barron’s book (2016 i think). I was wondering if the Barron’s book might work better for me since the problems are supposed to be a bit harder and will prep me better for the actual exam. Also, I’ve always used Barron’s for other exams and only picked PR this time because the Barron’s book wasn’t in stock.
So stressed. I think I have good chances at a 5 in Mechanics, but E&M is so frustrating. I’ve managed to knock down Electrostatics, but I can’t wrap around some circuits and most magnetism FRQ!!
Yo guys may the F = mg + kQq/r2 + BIL - kv be with you and wish me good luck tomorrow
Reminding myself: copying equations off the formula sheet earns you points on FRQs!!!