JoeDaWolf

nice icon...i got my scores back...5 on bc calc and 5 on physics b

http://www.sciam.com/askexpert_question.cfm?articleID=0003302E-388B-1C71-84A9809EC588EF21&catID=3&topicID=13

you can also define every astroid in the astroid belt a planet. they all orbit the sun.

i don't find them hard...it's just that this one had so many new applications of bc topics that the college board has never presented before. It was harder than previous years, but I'm pretty sure that they are going to lower the scale for people to get 5's.

yea...BC there's no high school seniors here who are took the ap exam?

Also, a hard part about physics is applying mathematics to problems that exist in the world. most people aren't good at applied mathematics becuase their brains don't think like that ~Wolf

If infinite energy existed, then nothing else could. Infinity, by definition, is conceptually the bgigest number. The universe would have to be infinitly large, with energy filling every dimension, and every space availible, (Along with being present for every fraction of every second.) If infinte energy existed, we wouldn't be around to debate its existence ~Wolf

The distance that light travels / time it takes the travel the ditsance < c, but it doesnt mean that the photons are travelling less than the speed of light. The photons have to enter the medium, get absorbed and emmited by all of the particles that stand it the path of the photon, correct? I know that it takes photons around 30,000 years to escape the center of the sun, going through a "random walk." ~Wolf

The MC was pretty easy. But wow...the free response. 1,4, and 5 were easy...they were the ab topics. 2,3, and 6...man. Each problem had at least one part that almost nobody in my class got right. I'd never seen some of those types of problems before. 6c: The differential equation! Omg! Question 3, with the derivitives with respect to y (i got that right...but then converting it to polar and integrating it there!) Also, the parametric questioin might have well just castrated you right there. I'm confident I did well, but I can't imagine how far down they are going to redo the scale. ~Wolf 1. Volume between sqrt(x) and e^-3x 2. parametric with dx/dt = -9(cos)(sin) and a cusp at B. 3. hyperbolia...or whatever it was. y^2-x^2=1 4. Kinda like the 1995 "hump check". Line with semicircle. 5. EASY. I'm suprised they didn't make it a cone. THis was the coffee pot problem with r=5. 6. Taylor series...which I thought was cos(x) Those tricky bastards. Any views?

Scientists originally thought that electrons orbited the nucleus of an atom because that's how the planets acted. They were wrong. You can't make the assumtion that everything that happens is like another naturally occuring phenomonom. ~Wolf

Didn't einstein win a nobel prize for explaining what happens when photons hit electrons? E = (1/2)mv^2= hf - Fc*f The photons give all their energy to both releasing the electron (Fc*f) and transfering the energy to the electron (hf). I don't believe he ever mentioned momentum ~Wolf

There is evidence...most biology books talk about the experiments with high voltage and several amino acids. The leading theory/proposal is that little bubbles of amino acids existed on the surface of oceans, and lightning hit one. many of them, which created the first proteins. Then these formed single-celled organisms. There's no issue with conservation of energy. The energy went into 'fusing' the amino acids together. It also converted into heat energy and some of it got lost in the enviornment. ~Wolf

When I first read the article, I thought "anthropic principal." Included with that notion is the idea that because time is created with the start of the big bang, there's no known universal timeline that states whether or not there have been 10,100, or 1000 universe before us. Matter cannot be created or destroyed ("Recycle: Save the universe!" I can imagine the bumper stickers right now:)) As for the miraculous statistical events, scientific american's most recent issue has a stunning article in it: The title of the magazine reads: "Infinite Earths in PARALLEL UNIVERSES Really Exist." "Not only are parallel universes--a staple of science fiction--probably real, but they could exist in four different ways. Somewhere out there our universe has a twin." http://www.sciam.com/article.cfm?colID=1&articleID=000F1EDD-B48A-1E90-8EA5809EC5880000 "One of the many implications of recent cosmological observations is that the concept of parallel universes is no mere metaphor. Space appears to be infinite in size. If so, then somewhere out there, everything that is possible becomes real, no matter how improbable it is. Beyond the range of our telescopes are other regions of space that are identical to ours. Those regions are a type of parallel universe. Scientists can even calculate how distant these universes are, on average. " "And that is fairly solid physics. When cosmologists consider theories that are less well established, they conclude that other universes can have entirely different properties and laws of physics. The presence of those universes would explain various strange aspects of our own. It could even answer fundamental questions about the nature of time and the comprehensibility of the physical world. " Not only does the article suggest that after eventual distances, there are EXACT copies of you, but in the universe, there exists EVERY possible combination for EVERYTHING. An entire universe devoted to your front yard having one less blade of grass...AMAZING! ~Wolf It seems that the anthropic principle survives another beating

what's the first F? emr? ~Wolf

i got my ti-83+ before the ti-89 came out

did you just plug that into your ti-89, or do you have a method perchance?

i've been trying this... i think in class, we would just use the calculator i can't find the right parameters to use partial fractions i can't use trigonmetric substituition However, the fact that you have that exact answer, which checks out with the calc, means that there's probably some way to do it...hmmmmmm ~Wolf

nice lil identity

AHAHAHA...expcet we ti-83 users have the last laugh...most of the peeps in my calc class have admitted that because of their 89s, they've forgotten how to do integrals easily (ap test thursday)...in all of my practice tests, i always try to do the integrals by hand.

rag's correct. in the case of intg(lnx), if you make lnx = u, then your dv=1. your dv needs to be present, not your v. ~Wolf

there is a calculator portion on the ap test for calc 1 and 2. theoretically you don't need it, but if the problem calls for integral of (sin(x)^2 - cos(x)^3 dx) from 0.3 to 1.7...then u need it ~Wolf P.S. I don't know if this goes on in other schools...but do all you TI-89 people think your sooo special? In my calc class, they think that they're god's gift to earth for having a machiene that produces variable integrals and derivitves TI-83+ is good enuf for me

For a while now, I've been wondering about the actual % of matter that collided with anti-matter at the time of the Big Bang. Do you have a source/site with further information, or did you make up the number based on the fact that visible matter only makes up 5-10% of the accounted mass in the universe? ~Wolf