SAT 2 Physics Thread

Test Preparation
1

<p>what did u guys think? do you think the curve is going 2 big?</p>

<p>i thought it was hard! =(</p>

2

<p>Me too. well it was okay. i was going through it and i felt like i had no idea. At the end though, i only left 5 blank.</p>

<p>What was the answer to the question:
"a ball going in a vertical circle, and at point P [lowest point] what is the direction of the net force?]
I put there is no net force, since all the vectors looked odd to me.</p>

<p>and also the one about:
"E=hf-w, releases energy, or something - reason for it is because of..."
Choices were like, Heinzberg's uncertantiy principle, electrons are quantized</p>

<p>and then waht about:
"Q1 is work done to a system, W is work done by the system, and Q2 is the heat released by the system. What is the equation that follows the thermodynamics principle" or something like that.
choices were like: W = Q1+Q2, Q1 = Q2-W, Q1< something, i dont really remmeber the choices.</p>

3

<p>well for the 1st q u asked...i put net force up...its moving in a circle...</p>

<p>2nd- i left that one blank...but i'm pretty sure it's conservation of energy cuz my friend's dad drove me home and he used 2 be a physicist and said conservation of energy</p>

<p>and the 3rd q i put A i'm pretty sure it was like q1= W + q2</p>

4

<p>I've been practicing with the Kaplan, and I think this test was pretty hard... there was one question on astronomy that was really weird that I had to leave blank because I had no idea what it was.... I usually leave less than 2 blank in practices with 10 minutes left over... this time I left maybe 5-6 blank and finished the last question just before time was up...</p>

<p>LoJT:
Your 1st question-- you were correct. Rilla, you are wrong. Because they specify it is a VERTICAL circle with gravity having an effect, the Centripital force cancels out the gravitational force, resulting in no net force.</p>

<p>2nd question:
You are confusing 2 questions I think... It said E=hf-w is based on what principle... The two choices I was switching between were Energy = Matter (E=mcsquared) and conservation of energy. Although technically E=mcsquared does work, if you step back and look at it from a simpler view without going to far into it, the -w part shows that it's talking about conservation of energy, so I chose that one. Seems right.</p>

<p>Your 3rd question was also a hard one for me... The correct formula is Q1 = Q2 + W, but that's assuming the system is 100% efficient, which is physically impossible really. So I was looking that maybe Q1 > Q2 + W was the correct choice, but then I noticed it said "a CLOSED system"... so that made me choose Q1 = Q2 + W. I'm not 100% sure on that one, but I feel pretty good about it.</p>

5

<p>bump! did anyone else take physics??????????</p>

6

<p>rilla: for the 1st question you talked about I think the answer was mv^2/r because the free body diagram/formula at that point is Tension - MG = MV^2/R</p>

7

<p>The question he/she is referring did not have equations as choices, but direction...</p>

<p>However, there was another problem that asked for the centripital force formula which was (mv^2)/r</p>

8

<p>there were two questions that had to do with the vertical circle </p>

<p>the first one asked for mv^2/r while the second asked for the direction after cutting the string off</p>

<p>i put direction like swerving upwards because there is both tangential acceleration and centrip acc at the moment it is cut off</p>

9

<p>NEOecd999- if there was no net force specifically pointed to the center of the circle, then the ball would not accelerate upward. it would just...sit there. When was the last time that happened in the middle of swinging something in a circle?</p>

<p>-it would be correct, however, if the ball were not in motion and just hanging on the string. however, i don't think that was what the question said...</p>

10

<p>I believe the heat question is Q1=W+Q2, because i'm pretty sure it was a cycle. </p>

<p>more questions I wasn't sure about...
-Experiment showing variety of colors: Soap bubble, prism, diffraction grating. I put soap bubble and prism.</p>

<p>-Light bulb intensity: Person moves from 10m away to 5 m away from a light bulb. Intensity increases by what factor? I put 4 but wasn't sure. </p>

<p>-Two people looking at the mirror and its image: One person moves back and the other moves toward the mirror. What does the image distance seem like? I put it doesn't change.</p>

<p>-One with crazy circuit and 5 switches: Which one would damage the circuit? I put Switch 5.</p>

<p>-Heat pollution: Can you remove it? I put "No, b/c heat can never completely be converted."</p>

<p>-Picture with two springs with the ball going back and forth: When's the upward force greatest? I put the second distance they gave us, whatever it was..</p>

<p>-Heat transfer in a room can be reduced by: I put increasing the thickness.</p>

11

<p>One with the tree image through a pinhole: I put real and inverted.</p>

12

<p>best_wr
i put the same answers
except>
1. i ommited the mirror problem
2. the answer to the circuit problem was switch 2, i believe</p>

<p>can anyone recall the vertical circle problem? i think there were more to it.
i said the acceleration was upward.</p>

13

<p>did you guys think it was hard?
i'm in ap physics c
and i thought it was tougher than test from the real sat2 book
i omitted 2 questions.</p>

14

<p>Wow, great memory, I had forgotten these already.</p>

<p>-Experiment showing variety of colors: Soap bubble, prism, diffraction grating. I put soap bubble and prism.</p>

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<p>-Two people looking at the mirror and its image: One person moves back and the other moves toward the mirror. What does the image distance seem like? I put it doesn't change.</p>

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<p>-Picture with two springs with the ball going back and forth: When's the upward force greatest? I put the second distance they gave us, whatever it was..</p>

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15

<p>For the Switch problem - it was the only switch that completed a circuit with the voltage. [It was like the switch, first one to the right of the voltage.]</p>

<p>Mirror I said that the person stepping closer, the image gets closer. the person moving backwards, the image becomes further.</p>

16

<p>let's make a AIM room. SAT Physics.</p>

17

<p>so what's the consensus on the switch?</p>

18

<p>For the switch one:
It was the switch nearest the battery. I forgot which one, but it would make the current short-circuit because there were no resistors. </p>

<p>I thought the mirror one was hard...</p>

19

<p>Hah, I completely bombed this. I expected it though, because I really only know mechanics. Hope I did better on Math IIC and US History.</p>

20

<p>Switch 3 is the answer - short circuit because no resistors</p>

<p>i think i got 2 wrong in addition to omitting 2</p>