**Official SAT II Physics December 6, 2014 Thread**

<p>Do you guys remember the K_max question that gave you a graph with three lines?</p>

<p>Tbh it wasn’t as bad as all those crazy rumors I heard preceding the test. Imo, the practice test in the blue book was like 10x harder. That said a few questions
1)On the question with the wires of differing length, is current constant for all 3 ?
2)Resistance of widest wire is lowest right?
3)For the one with the diagonal force F acting downwards on the object with the horizontal component as f, was the answer f/cos(theta)?
4)The questions with that object 3R from earth’s radius, is the force 1/9a when it’s that far away?
5)For the line of best fit, did do u guys put upside down V,crooked line, or some other line? -I just realized a “line” of best fit probably can’t be bent… -_-
6)For the question with the object accelerated 2 m/s for 3 seconds, what did you guys put for work? I guestimated 30 J.
7) When you had the parallel circuit with like 6R and 3R, is it like 6R>3R>parallel combination of the 2?
8) Left this one blank, but just curious, what was the example of a fractal?</p>

<p>It asked which was not an example, I think I put the one of the insect but idk</p>

<p>I wish I remembered all the questions so I can know how many I got wrong :(( </p>

<p>what the hell is a fractal yea that was a huge curveball</p>

<p>@Ausername91
7) was not something like a r, a parallel r and r(total)?</p>

<p>I put the mud crack for the fractals question but now I think it’s the insect shape. Darn</p>

<p>no one has stopped to inquire about…
WHY LINEAR REGRESSION IS ON AN SAT PHYSICS TEST</p>

<p>Don’t remember that on the test ^^</p>

<p>Resistance is defined by the equation: p(constant)*l/A where resistance is inversely proportional to the area of the wire and vice-versa with length. </p>

<p>In terms of Satellites orbiting the earth the centripetal force is equal to the gravitational force thus GMm/r2 = Fc = mv^2/r.</p>

<p>When resistors are in series a circuit they will have a greater equivalence resistance that any one resistor(you can derive this from the V = IR aka ohm’s law equation –> V tot/I tot = V1/I1 + V2/I2 + V3/I3… and since current(I) is the same across a series circuits you get the equation Rtot = R1 + R2 + R3 etc(you may also this of this in terms of the resistance equation where as length goes up resistance goes up)). </p>

<p>For resistors in parallel the equivalence resistance is the less than any one resistor(you can also derive this from ohms law Vtot/Itot = V1/I1 + V1/I2 + V3/I3… where V is constant(Kirchhoff’s law of Vrise = Vdrop) thus you get 1/Rtot = 1/R1 + 1/R2 + 1/R3 etc. (you may also think of this in terms of the resistance equation where Resistance inversely proportional to area)).</p>

<p>I will admit I got the last one wrong(because I misread one of the answer choices) but fractal structures are something with repeating patterns.</p>

<p><a href=“Fractal - Wikipedia”>http://en.wikipedia.org/wiki/Fractal&lt;/a&gt; </p>

<p>YES I GUESSED ON THE 5/3 AND 3.2 wooooo</p>

<p>How did you guys get 3.2? Wasn’t it 2.8? </p>

<p>@ausername91 1. The longer the wire, the more the resistance of it, so no.
2. yup, the wider the wire, the less resistance it has.
3. I thought about that but if the required force is horizontal and it’s acting at an angle (theta) then shouldn’t it be Fcos(theta)?
4. yup, g is right 1/9 of its usual intensity there.
6. I forget what the answer was, but you should’ve just used s=(0.5)(a)(t^2)
7. yup, the combination of two resistors in parallel is always lower than the individual resistors, themselves.
8. Fractals are repeating patterns, they don’t have to be symmetrical but somewhat of the same pattern. IMO, the thing with mud is that all the cracks will look somewhat similar, so I put insects. </p>

<p>@omarhaider‌
For your first answer, aren’t the wires in series? I’m not really sure. I know the resistances of each wire are inversely proportional to cross sectional area, but isn’t the current constant through each? Clarify pls haha</p>

<p>What was the question people are saying are 3.2 and 2.8?</p>

<p>What did you guys put for the distance vs time plot line of best fit?</p>

<p>@Dynasty21‌ yes, current is constant through each if its series. My mnemonic for remembering is R, I,V is to +, =, +</p>

<p>do you guys remember any other questions</p>

<p>oh ya what was the answer to the adiabatic process one the thing where two of the roman numerals were pressure decreases and volume increases</p>

<p>I said upside down V</p>

<p>was parabola an answer choice?</p>