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I just took this exam. It was manageable, but I felt rushed to go back to problems I had skipped and was thinking about while doing the other ones. I think this'll have a nice curve considering it's October and physics is a full-year course and it was relatively hard.

By Prada (Prada) on Saturday, October 11, 2003 - 01:15 pm: Edit

it was hard
can i get over 700 if i omitted like 12???

By Jokemaker (Jokemaker) on Saturday, October 11, 2003 - 01:16 pm: Edit

you could possibly get an 800 ommitting 12...

By Andy7733 (Andy7733) on Saturday, October 11, 2003 - 01:21 pm: Edit

hard test

By Smac86 (Smac86) on Saturday, October 11, 2003 - 01:25 pm: Edit

Very hard... left 6, got about 10 wrong... how much would that bee? Had no time to complete it- i'm sure i'd have maxed it if i had time thouygh

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:36 pm: Edit

well here is the grid from my real sat2's fro ur raw score

63=800
61=790
59=780
57=770
55=750
53=740
51=730
49=720
48=710
46=700

well i went into this test just hoping for 750. seriously though, i think the curve for physics is the best curve of any SAT. you could omit 12 and still get 800 (at least in this one ^). Anyway, even though the curve is good, by no means is this test easy. I breezed thru the beginning and middle, but there were some real tuffies near the end. especially with how they word their problems. i found myself constantly skipping two or three at a time, but in the end, i ended up omitting only 5. I think I will be satisfied with anything above 750. still, tho, an 800 is so nice and round...

i got so sick of those electric field problems. wires and meters and current AHHH

hey eurostar can u explain why the curve might be good since its october? i hope your right, but why do u think it will be nice curve.

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:38 pm: Edit

actually i made mistake in the grid. plug in 760=55, and then bump all the rest of the scores down by one. i.e., 45=700.

By Andrew123s (Andrew123s) on Saturday, October 11, 2003 - 04:44 pm: Edit

Anyone want to chat on aim about any of the problems?

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:48 pm: Edit

sure make a chat i will go

By Physicsstud (Physicsstud) on Saturday, October 11, 2003 - 04:50 pm: Edit

Andrew 123 how were the Spark Notes practices exams in comparison to the Test? I also took it today but didn't use Spark notes. I'm going to retake it again in November.

By Andrew123s (Andrew123s) on Saturday, October 11, 2003 - 04:50 pm: Edit

Chat room: PHYSICS26432

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:51 pm: Edit

can we make a poll of how many of you here took the SAT 2? i ehar that this sat 2 isnt that comon among applicants, so maybe that will help us if we do well. it seems that there have been 5 here already including me.

when u count yourself, just put quotes around your number. i.e.: I would be "5". this little post should be interesting. next person, put "6" and so on. but u figured that out, i mean, you took the sat 2 physics and everything!

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:51 pm: Edit

can we make a poll of how many of you here took the SAT 2? i ehar that this sat 2 isnt that comon among applicants, so maybe that will help us if we do well. it seems that there have been 5 here already including me.

when u count yourself, just put quotes around your number. i.e.: I would be "5". this little post should be interesting. next person, put "6" and so on. but u figured that out, i mean, you took the sat 2 physics and everything!

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:54 pm: Edit

andrew how do u get to that chat? aol or what sorry im not chat expert

By Andy7733 (Andy7733) on Saturday, October 11, 2003 - 04:55 pm: Edit

almondjoy: the reason its a good curve, hopefully, is that we're the slackers that didn't take the test in june or may, immediately after finishing a physics course. so hopefully, there will be lots of slackers, and this will pump up the curve.

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:55 pm: Edit

how do i go to chat? aol or what? sorry i dont know much about chat rooms

By Andrew123s (Andrew123s) on Saturday, October 11, 2003 - 04:55 pm: Edit

Sparknotes were overall pretty good. They didn't cover any astophysics (e.g. why the universe is expanding), but I think that was just one question. The exams were pretty comperable to the real one, though the real one might have had a few harder modern physics and thermal physics questions. Then again, the dests are different one each date, so it might just be this test.

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:57 pm: Edit

andy that would make sense, but i think the curve is made before the test is given, based on the difficulty of the test. i.e., the amount of easy, med, hard questions and such

By Andrew123s (Andrew123s) on Saturday, October 11, 2003 - 04:57 pm: Edit

Right click anyone on your buddy list and click "Send Chat invitation," and then change the person you are inviting to yourself and the chat room to PHYSICS26432.

Andy, I think the curve is determined before the test unfortunately.

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 04:59 pm: Edit

for the expanding universe one, was it I and II, red doppler shift and cosmic radiation? i dont think there was a I II III option.

By Andy7733 (Andy7733) on Saturday, October 11, 2003 - 05:01 pm: Edit

yeah i suspected as much, but maybe the college board takes our predicament into consideration.

they'll probably punish us by giving us a smaller curve...*grumbles*

By Almondjoy (Almondjoy) on Saturday, October 11, 2003 - 05:03 pm: Edit

come join the chat

By Andrew123s (Andrew123s) on Saturday, October 11, 2003 - 05:06 pm: Edit

Right, I chose I and II.

By Canadian_Idol (Canadian_Idol) on Saturday, October 11, 2003 - 07:49 pm: Edit

at the beginning there were 5 graphs with a block jettisoned up a ramp...what did you guys choose for the graph of speed of the block versus time? Doesn't it decrease and then increase again?

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 12:59 am: Edit

It does. That should be a V. What else was asked about those 5 graphs and the block going up the ramp? Was there any accelleration graph on the whole test that was a diagonal line?

Also, does anyone remember any questions about the KE vs. time graph later in the test?

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 01:00 am: Edit

no but i remember running out of time later in the test.

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 11:03 am: Edit

Anyone remember what they got for the question about the window and tempuratures/areas/thicknesses, the wierdly shaped conductor with bumps, and the question about the pressure in a boiling liquid?

By Misterpeachy (Misterpeachy) on Sunday, October 12, 2003 - 12:53 pm: Edit

Hey-

I just took the SAT II yesterday as well...
Water boils when the vapor pressure equals the atomspehere of the water.
The heat transfer problem was the one with the lowest temp (17C) and the greatest volume of wall, I think that was 17 degrees with a wall area 10 and thickness .18cm or whatever.

-007

By Drewshaver (Drewshaver) on Sunday, October 12, 2003 - 01:36 pm: Edit

what did u guys get with the spaceship going at .6c, and the particle going .6c the other way? the question was how fast is the particle in reference frame of the spaceship.

By Almondjoy (Almondjoy) on Sunday, October 12, 2003 - 02:09 pm: Edit

i got greater than c, caus ei just plugged in 1 for c and got 1.2 or summing

By Almondjoy (Almondjoy) on Sunday, October 12, 2003 - 02:11 pm: Edit

can anyone who compiled a list of the questions (i.e. andrew or ronguluad ) please sned them to me. i mean, if u wrote down and recalled like 30 or 40 questions from the test can u email them to me. i will do my best to add some that i remember so that maybe we can reconstruct the whole test. i would like to analyze how many i might have gotten wrong and im sure you guys would like to know as well. email it please, since there wont be any "reprocussions" this way

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 04:15 pm: Edit

Misterpeachy, the question about heat transfer had two answers that had the same volume: 9 area and .2 thickness, and 10 area and .18 thickness.

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 04:50 pm: Edit

a particle can't go faster than c though. I put between 0.6c and c...

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 05:05 pm: Edit

Right, a particle can't go faster than c, but in this case no particle is going faster than c. Two ships are going away from each other at .6c each, but nothing is claiming anything is going faster than c. I think the distance between the 2 ships is increasing at 1.2c. However, the question is what one ship's perspective is of the other. If we are in ship 1, it can't look like ship 2 is going away from us at 1.2c since the light emitted by the ship can't go faster than c. So does it look like it is going at c? Does time slowing down at .6c have anything to do with it? I'm not sure.

By Misterpeachy (Misterpeachy) on Sunday, October 12, 2003 - 05:40 pm: Edit

you need to use relitivistic velocity addition for which the formula is:

v(relative) = (v1-v2)/(1-(v1v2)/c^2). Vrel is the particles speed relative to a frame S' moving with speed v1 relate to a frame S (the earth) and v2 is the speed of the ship (s') relative to the earth. The equation becomes

.6=(x-.6)/(1-(.6*x)/c^2) since the ship is moving at .6c , the particle at .6c, and youre finding the vel in the ship frame.

you come up with .88c for the relative vel of the particle to the ship

Andrew - are you sure that it was 9 and .2 and not 9 and .18? There was a 9 area and a .2 thickness but with a higher temperature. Maybe I can't remember well.

-007

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 06:24 pm: Edit

Yeah, I did relativistic velocity, but I was thinking it might only be for a ship going and then shooting something in the same direction, not in the opposite. I guess that is right though. I put .6c to c, I was just second guessing myself.

As for the window one, it was definately 9 and .2 and 10 and .18 (both at 17 degrees, the lowest temperature). I just found somewhere online where it says heat transfer is minimized with smaller surface area and greater thickness. Who knows though, maybe that doesn't apply to this case. I don't remember the question on the test exactly.

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 07:35 pm: Edit

did that question ask for the setting for least heat transfer or most heat transfer?

By Stupid_Guy (Stupid_Guy) on Sunday, October 12, 2003 - 07:48 pm: Edit

when do we get the scores back?

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 08:36 pm: Edit

Least heat transfer.

We should be able to get our scores online at 4 P.M. on October 23.

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 09:24 pm: Edit

there was also a question about the gravitation on moon and earth...what did you guys choose for that? when you throw it goes 6 times as high on moon or you weigh 6 times as less on moon?

I thought since weight = mg and mass is constant the weight is 6 times as less on moon. My friend argues its the throwing distance though...

By Hsimpson2k4 (Hsimpson2k4) on Sunday, October 12, 2003 - 09:27 pm: Edit

It is throwing, I believe the answer said your mass is 6 times less, not weight.

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 09:34 pm: Edit

uh oh...one more question to my growing list of incorrect answers...=(

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 09:41 pm: Edit

oh and also another question dealing with galvanometers...i can't remember exactly what i put but the answer contained something about unchanging current...does anyone remember this question?

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 09:48 pm: Edit

Was it question 55? That was the one I omitted.

By Canadian_Idol (Canadian_Idol) on Sunday, October 12, 2003 - 09:53 pm: Edit

i don't remember too clearly but it was in that area.

any other questions that you guys felt uncertain about?

By Andrew123s (Andrew123s) on Sunday, October 12, 2003 - 10:32 pm: Edit

What about the "Which of the following would result in induced current?" and the three diagrams with magnetic fields and wires. Was it I+II? I+II+III? Something else?

By Skysurfer (Skysurfer) on Monday, October 13, 2003 - 12:45 am: Edit

that one was only 1 and 2 coz in the 3rd the induced magnetic fields were not changing. For the moon one it will be that 6 kg person weighs 1 kg on the moon isnt it obvious ??

By Lostgirl (Lostgirl) on Monday, October 13, 2003 - 01:18 am: Edit

The question asked about "least rate of heat transfer". . That would be possible if the thickness is greatest, area is the smallest and the temperature difference is the least( with the surrounding). so it cannot be 19 degrees but it is 17 degrees. heat from 19 degrees will be lost more rapidly than heat from 17 deg. so since we are to find the least rate of heat transfer, it is 17deg.


The very first postulate of Einstien's theory of relativity is that " light travels at a constant speed" and not "no particle can travel faster than light". so no matter what the relative velocities of the spaceships, the speed of light must be c. The question asked about the speed of light , right?

the question " which of the following will result in induced emf...." its I and II. the III doesnt cut/change the magnetic flux.

Canadian Idol,
The one about the galvanometer.....you are right there.


are you guys sure that it said that there was the masss that was 1/6 and not the "g". i remeber it to be "g"???

the last question was about the dierction of a charged particle projected perpendicuar to the mag. field. what was the charged particle..... a proton or an electron???

By Andy7733 (Andy7733) on Monday, October 13, 2003 - 01:53 am: Edit

the question said masses, therefore, 1/6 mass is not correct, as mass is constant.

By Canadian_Idol (Canadian_Idol) on Monday, October 13, 2003 - 02:01 am: Edit

well, if a particle goes to the speed of light, its mass will be infinite. I don't think it can actually reach c.

I dont remember the question about the induced current at all...does somebody wanna refresh my memory by describing the question?

I think the last question was a negatively charged particle.

By Rashmi (Rashmi) on Monday, October 13, 2003 - 07:18 am: Edit

Hehe...I'm no "6"....but I've forgotten most of the stuff by now.

By Misterpeachy (Misterpeachy) on Monday, October 13, 2003 - 10:02 am: Edit

Im pretty sure, almost positive, that at on my exam at least the question was (paraphrased):
"g is one sixth on the moon of what it is on earth, which of the following is true:
1)when you throw something up at constant vel, it goes 6 times higher than on earth (which is true and is the answer)
2)it goes 36 times higher
3)then the others were obviously wrong because they had soemthing to do with mass change.

-007 (USAPhO 2003)

PS: The equation for heat transfer b/w two volumes is:

Q=KA(T1-T2)/X where K is thermal conductivity, X is thickness b/w surfaces, and A is cross sectional area. Just found it in my usapho packet ;)

By Lostgirl (Lostgirl) on Monday, October 13, 2003 - 10:46 am: Edit

So the question asked about the speed of the particle and not light??? and the last question was a negatively charged particle....?? and it was masses and not weight!!!!!!so thats three more mistakes.... great!!!


what about the question with that had a capacitor and points (A-E) within it.

isnt the correct answer that "Force will be greatest at point A because the potentail at A is max"? "A" was closest to the positive plate and
F=(V*Q)/d. please correct me if i am wrong!!

so doesnt anyone remember anymore questions??

By Andrew123s (Andrew123s) on Monday, October 13, 2003 - 10:48 am: Edit

Lostgirl, it did not ask the speed of light. It effectively asked what speed ship 1 thought ship 2 was going when they were both moving away from each other at .6c. That would be the speed of ship 2 in ship 1's perspective, not the speed of light.

By Andrew123s (Andrew123s) on Monday, October 13, 2003 - 10:51 am: Edit

Also, the Force is equal everywhere for the quetsion with the parallel plate capacitor. F=qE. The charge and electfic field for all the particles were the same. There was also a question about the greatest potential. In that case, it was the one right between (in the middle of) the positive and negative plates. Since it was a positive charge, it was attracted to the negative plate at the bottom and it repelled from the positive plate at the top.

The last one was a negative charge. I did the right hand rule and reversed it (because of the negative charge) and I got counterclockwise (B), but everyone I've talked to said it was clockwise (C). Oh well.

By Skysurfer (Skysurfer) on Monday, October 13, 2003 - 12:21 pm: Edit

FOR THE moon problem : the d eqns stated that a body weighing 6 gms on earth weighs 1gm on moon or something.so tht was right.

By Andy7733 (Andy7733) on Monday, October 13, 2003 - 12:38 pm: Edit

no, weight is different from mass. mass is constant, weight depends on gravitational force. your mass doesnt change from 6g to 1 g, your weight does

By Skysurfer (Skysurfer) on Monday, October 13, 2003 - 02:18 pm: Edit

i know....i was talking about the weight. w=mg
so since weight on earth is 6 n or whtever then on the moon it becomes 1/6th = 1. The first two options got eliminated as s= ut - 1/2*g*t^2. so if g changes s does not change by the same as ut is present.

By Andrew123s (Andrew123s) on Monday, October 13, 2003 - 03:54 pm: Edit

Skysurfer, the question did not have an answer choice saying weight becomes 1/6th. The answer choice relating to that was mass was 1/6th (there were actually two answer choices relating to mass, and both were wrong). The others talked about how high it went.

You are right about the equation s = VT - 1/2*g*t^2. However, at the top of a throw, the speed of the ball, V, is always zero. Therefore, the equation becomes s = -1/2*g*t^2. The answer will come out positive since the value of g is negative. Therefore, a change in g will directly affect s.

By Andrew123s (Andrew123s) on Monday, October 13, 2003 - 04:09 pm: Edit

Actually, while g has a direct influence on s, I think we're using the wrong equation because we don't know anything about t. We should use vf^2=vi^2+2as.

We know vf is 0 at the top of the ball's trojectory. Let's say on the earth, this ball goes 1 meter high.

0^2 = vi^2 + 2(10)(1m)

We solve for vi and get it to be 4.47 m/s.

We then use that vi and use the equation again, this time with a different accelleration due to gravity, 10/6 or 1.67 m/s^2:

0^2 = 4.47^2 + 2(1.67)(s)

Solving for s, we get 6 m. So on the moon, a ball thrown at the same initial velocity will go 6 times as high as it does on the Earth.

By Skysurfer (Skysurfer) on Tuesday, October 14, 2003 - 07:28 am: Edit

nice....yeah ur right. I was so dumb tht i didnt even read the options correctly. sux !!! But the curve's gonna b good rite like in the real book ( 13 wrong = 800).

By Skysurfer (Skysurfer) on Tuesday, October 14, 2003 - 07:32 am: Edit

nice....yeah ur right. I was so dumb tht i didnt even read the options correctly. sux !!! But the curve's gonna b good rite like in the real book ( 13 wrong = 800).

By Lostgirl (Lostgirl) on Tuesday, October 14, 2003 - 11:05 am: Edit

Andrew, the charges were indeed the same between the two parallel plates... but what says that the electric field was same too?

also the potential cannot be highest at the middle ofthe plates. the definition of potential is" work done in bringing a unit +ve charge to a region in the elcetric field. hence the maximum potential would be when the charge is nearest to the positive plate.

but if we assume that electric field is the same(like you mentioned), then, the potential or the voltage will also have to be the same as, V=Ed, where d is the distance between the two plates.. and if voltage were same throughout, there would be no potential difference... and the capacitor wouldnt work altogether!!..

by the way, the charges mentioned in this question were +ve or -ve??

well for the last question, i thought it were a +ve charge and hence used the right hand rule and got "B".. so when you reverse it, it has to ce the "c" downward one.


i have ehard that this time we will be able to view scores online for free...is it really so??

By Andrew123s (Andrew123s) on Wednesday, October 15, 2003 - 04:55 pm: Edit

I'm not sure about the potential, but as for the force, a capacitor creates a uniform electric field with a magnitude of E = V / d. V is the potential difference. V = Ed, and since V is the potential difference and E and d are nonzero, the potential difference can't be zero either. Since the electric field is uniform the force has to be equal in all places in the electric field for equal charges.