<p>dielectrics included for physics B?</p>
<p>might we need to derive things like C1+ C2= C P for capactitors in the free response?</p>
<p>WIll frq be problems of derivation?</p>
<p>no dielectrics in physics B</p>
<p>Wait, do we have to remember how to derive moment of inertia? Because suddenly I can’t remember a lot of the formulas for moment of inertia for a lot of the geometric objects …</p>
<p>for physics B I seem to remember my teacher mentioning that they don’t ask questions about specific heat anymore, is that true? because I keep seeing them on old practice exams and I have no idea how to do them</p>
<p>vader: acceleration = 2g/3 and tension = mg/3</p>
<p>Yatta :</p>
<p>"The following problem is for Physics C students only:
Snipez, this question integrates (pardon the pun) all of the concepts you noted into one problem:</p>
<p>A wire has a time dependent current: I = 3t where t is measured in seconds. The current carrying wire is placed next to a square, conducting loop shown in the picture: <a href=“http://i30.■■■■■■■.com/2r7a749.jpg[/url]”>http://i30.■■■■■■■.com/2r7a749.jpg</a></p>
![http://i30.■■■■■■■.com/2r7a749.jpg[/url]](http://i30.tinypic.com/2r7a749.jpg%5B/url%5D){kind=link}
<p>The square loop has dimensions 3x5 meters as shown by the picture and the wire is 4 meters away from the loop.</p>
<p>Calculate the magnitude of the force on the wire at t = 20 seconds and give the direction.</p>
<p>This problem is very tedious and cannot be done in 1 step. If any of you need help, just ask me."</p>
<p>This is a nice problem except that I think Yatta forgot to state the resistance of the loop. (If I’m correct you could integrate to find the magnetic flux and thus the emf of the loop by faradays law. Then to find the force you have to use the magnetic force law for currents however you don’t know the current in the loop until you know the loops resistance.</p>
<p>No I think you can find the force if you wanted to. The problem of finding the magnetic flux and that of finding the magnetic force are very similar. In the first case, you are finding the differential area expression while in the second you are finding a differential length of the loop.</p>
<p>Anyways, does anyone know if we’ll need to find the B-field due to something besides an infinitely long current carrying wire?</p>
<p>The force law states dF = I (dl x B). Here B is the magnteic field created by the straight wire and I is the current in the bent loop. From Faradays Law we could get the V voltage of the loop and from Ohms Law (V/R)= I we could then get the current of the loop if only we had R…</p>
<p>^Yatta! That is correct!!! NICE WORK 
[I know it was pretty straight forward, but a lot of people in my C class got that question wrong…don’t know why though…lol…]</p>
<p>MJ582, nvm you’re right, well I think if you’re able to find the general expression for force and magnetic flux you’re in good shape.</p>
<p>AreRC Circuits present on the B test?</p>
<p>there arent circuits with >1 batteries on physb right?</p>
<p>Good luck everyone.</p>
<p>gl all! I’m probably going to get a 2 or 3 but w/e, I’m gonna do a lot better on the SATII in Physics.</p>
<p>Yea, you are right, I did forget to put the resistance down, my bad. And that is the correct way to do the problem, congrats!. If you really want to go through the calculations, let the resistance = 1 Ohm.</p>
<p>Oh em gee, after this and then after physics in June SAT II, I’m done with Physics FOREVERRRRRRRRR NEVER AGAIN, NEVER! (IF I do well in June that is…)</p>
<p>SATII physics subject test is hard… i though it was equal to AP questions… granted, you can get a 66/75 on that test and still get 800… but it’s hard… i’ve made 5’s on three practice ap physics b tests, but that didn’t matter when i took the satII physics… it’s just plain hard (i thought)</p>
<p>Yeah, the day before my May SATII I ended up not going to my exam cuz I kept getting about 20 questions wrong each time so I thought it was pretty pointless writing an exam I know I’m gonna fail miserably.</p>
<p>grrr…“the super generous” curve doesn’t really help</p>
<p>is the equation from waves, beta= 10 log i/ I0 included? its on page 335 of pr.</p>
<p>also, is it safe to think that any formula with logs won’t show up on mc?</p>