<p>Even if they wanted something besides use a ruler, they can’t penalize at all. They didn’t say anything about not being able to measure by hand. If any of us who said use a ruler gets penalized, that’s not cool!</p>
<p>^It asked for an equation and quantities to be measured. It wouldn’t make sense to ask that if you simply measured it. </p>
<p>(i agree with you though, i think you found a loophole)</p>
<p>also…(im not sure if its a loophole or not) for the fluid question they asked for the weight for the whole apparatus…so do we just literally add all the weights up? including the beaker, the ball, and water?</p>
<p>It depends on whether they said the volume of the water was the volume before it was poured into the beaker or after it was poured in with the ball added. I thought it was the total volume in the beaker, so weight would just be (rho)Vg + Beaker but thinking back to it, I think they meant the volume of the water before it was poured into the beaker. If so then it would all 3 components.</p>
<p>For the lab question, my set-up was the laser pointer, the screen, and the metric ruler.
My process was to fire the laser pointer thru the gap and at the screen, then measure the distance between the fringes with the ruler. From there I isolated the separation of the metal strips with Young’s formula.
Does that sound like full credit?</p>
<p>Also what was the physical explanation for the gap on the copper spheres question?</p>
<p>I said because charge exists in discrete quanta</p>
<p>@ kevination, I got the same set up as you did, but it seems wrong because don’t you need the prism to the divide the light ray into more lights rays on to the wall as fringes, and then you can calculate the division. Using only a laser beam with out the prism would just make a laser beam going through the slit and becoming a dot on the screen.</p>
<p>^ no. The laser beam shoots out polarized light rays, but there are so many of these beams that some diffract out to form an interference pattern. There is no need for a prism.</p>
<p>so I only need 1 slit in order to have an interference pattern based on the wavelength of the laser beam?</p>
<p>what books did you guys use? would you recommend them?</p>
<p>^ Princeton Review. And yes, they had a lot of multiple-choice questions that were very similar to the real exam.</p>
<p>I hav no idea wat went wrong with that test. I took a practice test the day before my actual exam and i got 8 wrong on the MC part of the test (62/70), but on the real exam i think i got about 20-25 wrong…thts still a 5 rite? I think tht on the FRQ part i think i answered evry question but on half of the questions i got almost everything rite, and on the others i got 50-75% of all the points for the problems. Do u guys still think i gotta 5?
Its weird cuz every other person i talked to said tht every single ap test this year was uber hard in at least one of the parts.
i dont kno about u guys but i thought that the slit experiment problem was SOOOOO easy. I think that as long as u either understood the slit-diffraction theorem or young’s experiment, then all that u had to do was replicate it using the provided materials.</p>
<p>o ya and btw we have ib physics/ap physics b combined in one class because there werent enuff students (we had a total of 10 students haha and out of those students 3, including me, took the ap test, and 3 other people took the ib test).The downside was tht we had to follow an ib physics book by Chris Hamper and i had to self study several topics.</p>
<p>@collegebound41 if u want some ap physics b prep books sorta like sat/act prep books, then these r some good suggestions for some publishers u mite wanna check out: barrons, princeton, 5 steps to a 5, and u can prolly look for other publishers that do sat/act stuff (lik Kaplan and stuff) cuz they will prolly do ap physics too. O ya and just keep note of this:</p>
<p>Princeton(Cracking the Ap physics exam)-has very good lessons and is good at teaching some theory and actual physics lessons without looking at a separate textbook. However, make sure that u kno that princeton often has practice exams and problems that are easier than the actual ap exam. </p>
<p>Barrons-Barrons are arguably the hardest prep books. However, if one can handle them, they will benefit u greatly. The questions and practice exams are actually harder than the actual ap exam. However, if you think about it, if u master exams from the Barrons, then u will get a really good score on the actual ap exam because the actual exam is easier. </p>
<p>5 steps to a 5- The only reason that i dont lik this book is because it tells me how to manage my time, which i lik to do by myself lolool just my preference but it is good for management. Also, there are many physics lessons that cud help u out</p>
<p>Remember, these are PREP BOOKS not TEXTBOOKS. I dont no wat to tell u for textbooks becuz i had to take the ib physics book (read my above post). I wudnt exactly recommend reading the ib physics book because it is different, but if u do, then make sure that u read the course guidelines for the ap test at collegboard.com because there is extra and unnecessary info in the ib book.</p>
<p>i used Princeton review throughout the whole year. it complements the course and explains the concepts really well.</p>
<p>When will the scoring guidelines be available?</p>