<p>Can someone pls explain terminal velocity to me? I hate this kind of problem.</p>
<p>Basically when the maximum velocity is reached. And since the velocity any change anymore, there is No acceleration which means there’s 0 force. You can then solve for whatever you need to if you understand this. </p>
<p>Sent from my iPhone 4 using CC app</p>
<p>Also, know how to derive the equations for RC circuits and velocity with air resistance</p>
<p>@AstroBlue: For a charging circut containing a capacitor with capacitance C, a source of EMF E, and a resistor with resistance R, use the loop rule (where net voltage across one loop of a circut equals zero. One of Kirchoff’s Rules) to get an expression looking like this:</p>
<p>Emf-Vresistor-Vcapacitor=0 -or-
E - IR - Q/C = 0
E - (dQ/dt)R -Q/C = 0</p>
<p>To solve for charge, just solve using differential equations. I don’t think AP expects all of the work considering this is a standard form, so get yourself up to this point and then you’ll be fine putting Q=EC(1-e^(-t/RC)). Get rid of the Capacitance term and you got a function for V. For I, remember that (dQ/dt)=I and derrive the Q expression with respect to time.</p>
<p>Solve for discharing the same way. Just remember that the equation for charge is Q=Qo(e^(-t/RC)).</p>
<p>I’m not sure what you mean by the second one. Do you mean like an energy conservation with a W(non-conservative) term or what?</p>
<p>Anywho, I’m getting ready to take the exam myself. Good luck, all. If you have any questions, I’ll try and be around to help.</p>
<p>haha, i remember the derivations, I was just reminding people to know them because sometimes they ask you to solve differential equations on the frq.
by the second one, like, if they give you an object falling with a resistive force of bv then you would have ma=mg-bv or m(dv/dt)=mg-bv and you isolate variables and solve for v</p>
<p>Whoops! Heh, good thing the AP Lit exam wasn’t today.</p>
<p>But yeah, know those derrivations well. I’d also suggest knowing the E-field for continuous arc of charge one, obviously the gauss’ law ones, the velocity expression for elastic collisions (v1i + v1f = v2i + v2f), the less imortant RL circut derrivation, and possibly the derrivations for B-field from long wires, arcs, and solenoids/inductors.</p>
<p>I knew nothing on mechanics. I knew a little bit more on e&m. Predicted scores: 1 on mechanics, hopefully 2 on e&m…</p>
<p>For FRQs i just copied the equation sheet over and over and over again. xD</p>
<p>Mechanics is FRIGGING HARD!!! I have to retake it next year!</p>
<p>*** was up with that exam? CollegeBoard must be ■■■■■■■■ this year.</p>
<p>i had to ask the proctor for a bandaid during the exam cuz my ass was bleeding so bad</p>
<p>The Mechanics exam was the hardest exam I think I’ve ever taken.
I’ve never seen problems like those (and my teacher uses FRQs from the previous years to review with us)</p>
<p>hey i didn’t have time. I was like on number 27 when the proctor called time. but I already had bubbled B for the rest of the answers like 10 minutes before.
On e&m my guessing letter was d.</p>
<p>I hope i did well with choosing my guessing letter.</p>
<p>lol @salzahrah
CB didn’t even have the courtesy to use lube.</p>
<p>/oh my GOD. *** was THAT???</p>
<p>I got fuc%^&king raped on that mechanics test!!!</p>
<p>^Same. I’m hoping for a 4 but expecting a 3.</p>
<p>I here you… I even drew a picture of a rabbit being attacked by a dinosaur as one of my answers to the FR… Hoping for a 4, but maybe a 3 =\ *** is a torsion pendulum jesus christ that test was hard.</p>
<p>
</p>
<p>Yes!!! They better give you points for that.</p>
<p>But let’s be serious, who didn’t get raped by the mechanics test >.></p>
<p>…I felt completely violated.
Really.</p>
<p>Honestly, 75% of what I wrote was absolute BS. The 25% is probably wrong.</p>
<p>…There goes my 5.</p>
<p>I think i did maybe 1/2-2/3 of number 1 right, ummm, maybe a bit more than 1/2 of number 2 right (luckily if you get one part wrong but carry your answer over to the next, you can still get points so I did that on parts) and I’m pretty sure I didn’t get part 1 and 2 of 3, but I think i got the last parts of it 
E&M, I have no idea on the MC…Frqs, I thought I did decent…ish, I realized how to do one part of part 2 right after I left the room…I hate life >.></p>