<p>Gliese, I don’t know what you are talking about regarding the denominator, since I don’t remember there being numbers besides radius. Actually, I think that maybe there were two versions of some select questions, since I remember that question being about finding the period, and it gave you nonsense, but only one option was 2piR in numerator.</p>
<p>@JustPhysics - Yah, I was talking about the graph one, my bad, in which case the V looking velocity could have a graphed as a constant. I don’t remember the problem that you are talking about. </p>
<p>Can anyone give an explanation for the scope theta increase decrease one and the flux one? Also, what was the force felt by the 1.6Etothesomething charge going across 9 V Capacitor with like a 12 battery and a .02 radius?</p>
<p>@icecubes123
for the half life question i got 1 hr 20 minutes… </p>
<p>@lasern
i chose net force too… speed, momentum, velocity, kinetic energy all have v in it lol so i just eliminated them. proabaly not the right approach</p>
<p>azn, if you’re talking about the one with circular wires near a magnetic field, then yes i put that, but i was not very confident about it; I’ve barely learned anything about magnetism. I assumed that since part of the path of each moved perpendicularly to the field, they would all have some induction, but only… 3, I think was entirely perpendicular, and I don’t even remember what it said about movement of them or whether that makes a difference.</p>
<p>For the block and rotating wheel problem, I said the spring directly measured the coefficient of kinetic friction…since the block was moving relative to the surface of the wheel. Can anybody confirm?</p>
<p>Also would like to chime in and say this test was hard, coming from someone who’s had > 3 months of physics summer study.</p>
<p>I put the force of static friction. I assumed that the wheel would grip the block, hence static, not kinetic. Also, I don’t think it was the coefficient because it asked for a direct measurement, which would have been how much force was being applied to the left. You would need to know normal force to find the coefficient and i don’t think i was given, on top of the fact that it wouldn’t have been a direct measurement.</p>
<p>Yah Gliese is right. Static is like cars spinning off and things going into motion against friction from rest. It was definitely static. I still feel like the induced emf was lens’s law related though. Still probably did it wrong though.</p>
<p>Gliese, the wheel doesnt really grip the block. The problem said that the wheel was spinning at a constant velocity but the block wasnt moving. There is a kinetic friction onto the wheel by the block and by Newton’s 3rd law, an equal and opposite force applied onto the block by the wheel. That force will equal the tension force. So while the block doesnt move, the wheel’s motion makes it kinetic friction. MarkQuestion was correct.</p>
<p>A similar example that might clear this prob up, if I slide my hand along a table, you’d agree that there is some kinetic friction, no? If i held my hand in place, and then someone else slides the table from under my hand, that’s still kinetic friction. That’s essentially the concept here.</p>
<p>Ah, I see what you mean, and I think you’re probably right. Sorry for the misinformation, I just ignored that answer since I assumed that it couldn’t have been the coefficient since it said something about “most direct” and I automatically assumed it had to be the force being measured. The wheel does exert static friction before kinetic though, so I’ll hold out hope.</p>
<p>I agree with the point your making Shroud, but that wasn’t what the question was asking, at least in my test. However, there does seem to be some variance in how people here on cc are reporting their questions. Many people seem to be getting same set-ups with slight changes in what you are technically supposed to calculate or determine. My one was a block on a spring, under which was a wheel. The point where the wheel spins independently would be the point where max static friction is exceeded. Now if it asked about the force required to bring the independently spinning wheel to a stop, that would be kinetic friction. </p>
<p>justPhysics, I thought that all were 60/75 raw score = 800. Well technically 59.5/75. Certainly, this test was NOT an easier than average physics SAT 2, so the 60 raw is the shooting point I guess. It’s going to be tight for me. I can only afford 9 wrong after blanks are accounted for, and I see 3-4 wrong already… :(</p>
<p>ugh, i skipped quite a few, but felt sure pretty about the ones i answered, so i’m hoping for a generous scale</p>
<p>couple questions that bugged me: the one about the block projected up an inclined plane…what graph represented its acceleration?</p>
<p>also, the really simple one about the inelastic collision where two carts become stuck together, what was the answer for final velocity (if that was even the question, i cant quite remember) on that one? such an easy question, but i feel like a derp and i got stumped</p>
<p>****, I think I am going to have to cancel…I really needed an 800 on this and it doesn’t look like I got it. I guess I’ll have to take it next month with the Math II and study a lot this month :/. It has not been a good day… I can only afford 9 wrong with the blanks too but from what people are saying it looks like I more than that. I’m going to compile a list of answers and then see if I have missed more than that. </p>
<p>Ugh I really wanted to have this done with.</p>
<p>For the final velocity of the cart I got 3 m/s. And benevolent, I am pretty sure the answer was kinetic friction (I put static) because the wheel is essentially grinding against the rectangle - it is not moving along it. The wheel remains stationary.</p>
<p>JustPhysics do you remember how you got 3 m/s??</p>
<p>And in my humble opinion, I don’t think you should cancel your score. I really can’t imagine an admission officer thinking any less of you if you got a mid-to high 700 score instead of an 800</p>