<p>uhh, you do (T,hot-T,low)/T,hot... the temps have <em>everything</em> to do with efficiency.</p>
<p>Yup, 25% and 100J.</p>
<p>i think you can calculate efficiency another way</p>
<p>anyways, what did you guys get for the X-----Y------Z for mass on a spring</p>
<p>what did you get for the maximimum speed of the 20 N object lifted from a 12 V - 2A circuit?</p>
<p>P=IV=12*2=24
P=W/t=Fd/t=Fv
24=20v
v=1.2 m/s</p>
<p>The spring: 0 acceleration at Y, 0 speed at X and Z, ummm idk what other questions were</p>
<p>Capacitance – Greatest area (6) & smallest distance (1)
Graphs of velocity vs. time
- Constant magnitude and direction of force NOT in E (the one that was not a straight line)
- Reversed velocity is D(?) – the one where the graph has negative y-values
Resistors in parallel – R1>R2>R (or R2>R1>R)
Nothing can go faster than speed of light is theory of relativity
Ball dropped at height h at same time another ball is thrown with horizontal velocity v lands v [sqrt (2h/g)] away from each other
A person on a planet twice as massive as earth weighs twice as much than on earth.
Electric motor with 2A current and 12V pushes up object weighing 20N at 1.2 m/s</p>
<p>Minimizing earth’s mass increases the radius of the orbit of a satellite orbiting earth(?) </p>
<p>The “I have no idea” questions
- Quasar
- Electroscope
- Diffraction through slit towards point P
- Square wire w/ current moving through a magnetic field. What direction is the current?</p>
<p>I'm might be remembering some of these wrong...</p>
<p>quasar - origin of universe
electroscope - negatively charged ends (it was a negative rod, right?)
interference - some are increased, some decreased
loop of wire - clockwise</p>
<p>c8nmgr- got everything you had</p>
<p>Resistors in parallel – R1>R2>R (or R2>R1>R)
--> that one was R1>R2>r if you subbed in 10 and 5, you'd get 10>5>3.33</p>
<p>one-</p>
<p>electroscope..which question was that?
and are you sure about the loop of wire? =(</p>
<p>On the spaceship shooting the laser, did you have to know the speed of light, because I was more or less stumped and chose 2.5 * 10^8 or somthing like that. Noone said anything about knowing constants.</p>
<p>I can't belive I messed up on the capaciter one. I put the right answer and changed it afterward!
Worse still was the Resistor one (person above me). I replaced 2 and 1 into it and got the total resistance as 2/3, but then I messed up and used the total resistance with the inverse of the partial resistances!!! I only realized it a seconed before time was called too.
There were a few more I didn't know and some I know I got wrong, but hopfully it's high 700's/800 (Well I can dream can't I?)</p>
<p>I said no induced current for the square wire, because there was no change in magnetic flux</p>
<p>electroscope? you mean "how does an electron microscope focus?"? I said magnets, but I'm not sure</p>
<p>Interference at point P w/ wavelengths of .5 I said you can't do, because line isn't perpendicular (or b/c there's no angle or distance between points, but that's not a choice)</p>
<p>quasar--beginning of univ.</p>
<p>laser is 3E8, speed of light</p>
<p>This was bad. I thought I would do pretty well... much to my chagrin, we had not even covered half of the material on the test. My school does not offer an AP Physics course... I tried to study from Barron's book, but I've been so busy with projects and finals (it being the last week of school) that I never even got to crack the book open.</p>
<p>There was no induced current but not for the reason that iin77 said. It's because all the electrons would go to the bottom and then repel each other and go back. I don't remember a diffraction question with a point P but if you're referring to the one with 5.3 and 6.3 then the answer would be that it would be greater because the distance are one wavelength (or two, I forgot) apart meaning that it's in phase. As for the glass prism one, I'm pretty sure that every material has a slightly different index of refraction for every wavelength of light.</p>
<p>Yeah sorry about the electroscope. That's what I meant (I put magnetic field too, but that was basically a guess.)</p>
<p>Yep I put everything iin77 put for the same reasons except the interference at point P. (I put what One put: some increased, some decreased)</p>
<p>What about the "Increase speed of light going through glass/prism?" Choices were increase intensity, move prism closer to light, increase frequency?...I put something else. I forgot lol.</p>
<p>-> no induced current
-> electroscope was most likely magnets, but i put lens for some wierd reason -_-
-> laser do you just add the two speeds? so 3e8+2e8=5e8?</p>
<h1>Print your admission ticket for the Oct 6 SAT.</h1>
<h1>Your Oct 6 SAT is 126 day(s) away.</h1>
<p>:P</p>
<p>Prism I said angle of incidence, because that's based on the refraction constant of the prism... right?</p>
<p>5e8!?!?!</p>
<p>You just broke relativity. It's 3e8. Light moves at the same speed regardless of frame of reference.</p>
<p>postulate of sp relativity,</p>
<p>light is measured the same value (i.e 3 x 10^8 m/s) in EVERY inertial frame of reference</p>
<p>yea i just realized that =(</p>
<p>Btw, I can confirm the glass prism question is frequency of light.</p>
<p>Also, what was the answer to the question that asked for the correct diagram of light going through a converging lens. It was difficult to differentiate between B and C but I put B.</p>
<p>Haha loved acar's reaction to breaking relativity =)</p>
<p>%#&)@ at the prism... =(</p>
<p>I think diagram was B (top right?)</p>
<p>Couple more I remembered:
Tightening string/increasing tension increases frequency.
Boiling water. Increasing temperature leads to steam coming out at a faster rate (only)</p>