June 2008 - Physics

<p>what do you mean 'not "this" particular test" ??</p>

<p>Sorry...
That post was meant for grade inflation.</p>

<p>so for that one where there were all charges and it said which one has the greatest electric field on the center, was it the one with all of the 2q??</p>

<p>I believe so...</p>

<p>okay thats what im thinkin but Ownersinc on page 11 said otherwise. can anyone else confirm that it was the one with all 2q?</p>

<p>The moron who was invigilating our test didn't announce loud enough when we could start the second test!</p>

<p>As a result, I didn't know we could start (along with a lot of other people around me). I was getting really excited as I'm expecting a raw-score of at least 42 in Math IIC, which I gave first. Then this happened!</p>

<p>Started Physics 6-7 minutes late, means I did about 10 questions less than I could. Just expect 50 correct.</p>

<p>it was the one with all the 2q.</p>

<p>was the answer to the rocket question (A)? pushing with an oar (or something) to move back? i thought it was the Newton's 3rd law concept.</p>

<p>please answer if anyone knows! this question seems to have confused all of my friends.</p>

<p>no the rocket moves up because of conservation of momentum. the gas moves in the opposite direction, so according to law of conservation of momentum , the rocket is propulsed up</p>

<p>just like the boat, the rock is thrown backwards so that the boat can move forward</p>

<p>also, wat did you guys put for the momentum question? momentum of the original is opposite in direction or smaller magnitude or what?</p>

<p>reflected, incident, normal AND mirror all on same plane yea?</p>

<p>Waves 2T period question? did you guys put the point at the 2 wavelengths?</p>

<p>i also put throw stones.in the beginning with the graphs where it had speed vs time what was the answer when it asked you which is the graph in which the force is opposite velocity and then in which is the magnitude of the force minimum??i put c in both of them,a graph in which speed was at first positive and it was getting less.could someone plz try remember what you said on this one??thanks</p>

<p>what did you guys put for the momentum question? momentum of the original is opposite in direction or smaller magnitude or what?</p>

<p>reflected, incident, normal AND mirror all on same plane yea?</p>

<p>Waves 2T period question? did you guys put the point at the 2 wavelengths? (It was the big wave diagram with A-E points on it)</p>

<p>PLEASE answer. :) thanks</p>

<p>i put smaller in magnitude which i think is correct.reflected incident and normal on the same plane.point 2t at two wavelength.all theseare correct.can sb answer mine??and could someone do a list like on math cuz there are a lot of correct answers in this thread here and there.</p>

<p>1991 or anyone reading this, sorry for being slightly neurotic..lol, but for the reflected incident and normal on the same plane question, was there a very similar answer choice? i'm getting slightly doubtful as to whether i chose that one. i def remember i put an answer choice that included these wordings, 'same plane', 'normal', 'reflected', 'incident', but as to whether the 'mirror' was included in one answer choice or not...im not sure. :) thanks!</p>

<p>@student91:
the momentum question is smaller in magnitude.
if it's an elastic collision, then you can use the formulas for it and calculate the final velocity of the ball to be 0 (it stops and the other one moves)
if it's a complete inelastic collision, then the 2 balls would stick together, and the first ball would still have smaller momentum
if it's just general inelastic collision, idk ... im too lazy to prove it, but it should be right.</p>

<p>1-2.in the begining 2 segment questions about boiling etc.
3.distance between earth and planet when moving at 0.9c is greater than0 but shorter.
4.incident normal and reflected on the same plane
5.stopwatch for pendulum
6.4ev in the min energy in the photoelectric effect
7.3600C
8.inerference in black rings etc
9.northwest
10.u=20m/s when a object is thrown vertically and reaches hmax at 20m
11.proton as a hydrogen nucleus
12.positron in mass to charge ratio
13.alpha particle captures 2 e to become He
14.an object rises 6 times in moon than earth
15.circular field lines around a straight wire
16.satelite orbiting earth at 3r has 1/9<em>g
17.attract attract in iron-magnet fillings
18.tangential acceleration constant
19.fractals-insect body
20.the greater magnitude of electric field was that with 2q charges
21.masses on pulley are equal
22.scuba diver sees object higher
23.when gravity is taken off object moves tangential
24.f/m acceleration
25-26-27.waves at the begining one wavelength is in the second inercept,2T is on 2 wavelengths,point b is moving towards the top
28.y=x+ut+1/2at</em>t is object in incline
29.p is smaller in magnitude after collision
30.parabolic going towards opposite gharged plate(anyone remember if there was an electron or a proton?i do remember tah the upper plate was+++for sure)
31.tree is 0.025m
32.increase f increase k
33.voltage in parallel resistosr was 3V
34.capacitors store gharge
35.light rays emerging from tha water make a large angle to the normal
36.the speed of the truck that had 500kg dropped was 16m/s
37.rocket question throw a stone to make a boat move
38.vertical velocity vs time linear
39-40.the graph where the force is in opposite direction to motion and that with the smaller magnitude of acceleration where the same
41.the distance in the question with two wires was 2L
42.frictional force was 10N
43.all waves undergo diffraction
44.verticall component was Fsin60 and horizontal was Fcos60
45.the highest EMI induced was option d the one at the top of the circle
46.internal energy is 0 in isithermal segmant C
47-48.block on a ramp.PE was decreasing as the blocj is going down and force is increasing
49.a question about efficiency i think the correct answer was 1000J and 30%
50-51.2 questions about Fparallel were easy.the second was 1/2mg if i am right</p>

<p>there was also another question about inernal energy where it said smth abouy 2.0J and then smth about 0.5J but i dont really remember.i put 2.5J in this one
also another about a circuit with emf and two resistors R,r.i put switch oppen there but probably not.</p>

<p>For #7, keep in mind that while an amp-hour is 3600 coulombs, if 1 amp flows for only 0.5 hours, then it'd be 1800 coulombs. The only question is whether it was 1 amp... I can't remember.</p>

<p>FEW QUESTIONS:</p>

<ol>
<li>QUESTION - BATTERY has internal resistance r, connected to a Resistor R. How can you get the EMF of the battery between points A and B?
CHOICES:
-R=r
-R is small
-r is large
-Switch is Open
-Large CUrrent</li>
<li>As the distance increases between two parallel plate capacitors, what happens to the electric field between them (it was a graph)
-WAS IT A HYPERBOLIC GRAPh, WITH d increasing and E decreasing? I used the formula E=V/d</li>
</ol>

<p>-1991, I agree With all of yours.
By the Way, it was 2 Amps, so I=C/s, Is = C, C=(2A)(1800 s)</p>

<p>"By the Way, it was 2 Amps" -- damn, I hate misreading something</p>

<p>-switch is open - this essentially makes R infinitely large, which means the ratio of r/R is 0. The voltage drop across both resistors must equal the emf of the battery, and if R is infinitely larger, that means the largest voltage drop is across that resistor.</p>

<p>Vtotal = V1 + V2</p>

<p>Vtotal = I1R1 + I2R2</p>

<p>I1 = I2 (series circuit), so the greater resistor has the greatest voltage drop across it.</p>

<p>when the switch is open, there is no current, and the circuit is invalid.</p>

<p>If R is small, than r is essentially than</p>

<p>V = Ir1 + IR2</p>

<p>If R is small, IR2 = about 0
Than V=Emf=Ir1</p>