Hard Definition and 1000 Threads

AMC Question HARD! While doing the Year Eight AMC (Australian Maths Competition), I came across this diffucult question... (By the way, this isn't homework :P) "I have a list of twelve numbers. The first number is 1 and the last number is 12. Each of the numbers is one more than the average...

Does a hard drive weigh more when data is stored in it?

I've been going at this problem for at least 3 hours :cry: Just need to find the integral for: INTEGRAL(x^3e^x^2) / (x^2 + 1)^2 dxI've tried all kinds of different methods, filling up at 4 pages in my notebook! I think this is the closest I've gotten :confused: First I broke up the numerator...

The theme seems to be that Academia positions are far and few between, so it that the same for National Labs too? Thanks.

I don't want to "pirate" any movies, but would like to rip DVD's that I bought into my computer so I can put them on my iPod. Are there ways to rip copy protected DVD's with many chapters/episodes etc? Which software allows me to do it? Is it legal?

Homework Statement a 1000kg car negotiates a banked friction free track or radius 25m with speed 30m/s to what angle to the horizontal is the road banked? Homework Equations The Attempt at a Solution tried to calculate the normal force of the car, to find the angle between the...

Homework Statement A commuter airplane starts from an airport and takes the route shown in the figure below. The plane first flies to city A located 175 km away in a direction 30.0° north of east. Next, it flies for 150 km 20.0° west of north to city B. Finally, the plane flies 190 km due...

um, I'm having a hard time understanding some terms and equations in semiconductors, particulary 2 equations and 1 term(fermi function,density of state function, and fermi level). My understanding of fermi function is somewhat the probability of an energy state to be occupied by an electron. for...

Hi, I'm just wondering if anyone can help me with this equation: I need to determine the values of A,B and C from the given equation. \frac{A}{(x-1)} + \frac{B}{(x+1)} + \frac{C}{x} = \frac{5x^2+2x+1}{x^3-x} I've tried to simplify it by factorising the denominator on the LHS to x^3 - x...

Homework Statement \mbox {1. If f(x) is a positive and continuous function in [1,\infty)\ and\ \lim_{x\rightarrow \infty} f(x)=0 } \mbox {Prove or contradict:}\\ \mbox { If } \sum_{n=1}^\infty f(n) \ \mbox {is converget then} \ \int_{1}^\infty f(x)dx \ \mbox {is also convergent.} \mbox...

Homework Statement see attachment The Attempt at a Solution for part a): I tried to use the equation N2/N1= I1/I2 I got 12A, instead of the answer (24A) can someone please show me how to do this? I missed class one day, and now I'm lost

Homework Statement Given integers 4, 8, 7, 5. An inversion occurs when one integer is larger than an integer that follows it; thus, in the above arrangement there are two inversions due to 8 and one due to 7 or three inversions in all. There are twenty distinct possible integers arranged in...

Ok so I'm currently doing the calculus and vectors course (we sacrificed integrals to include vectors) And I'm finding that course really difficult. I don't know what it is but man no matter how much time i spend on it (atleast 3 hrs a day) i can't seem to get it. Well that's sort of a lie. I...

I understand the general aspects of how a hard disk drives works. I have gone deeper and have learned about the various types of magnetoresistance, both AMR and GMR. I understand the fundamentals of how these systems work compared to older units. But people keep telling me that the data...

Homework Statement A French and a U.S. submarine are moving directly towards each other during manoeuvres in still water. The French submarine is moving at 50.0 km.hr-1. It sends out a sonar signal at 1100.0 Hz. The frequency detected by the French submarine (reflected back from the U.S...

The girl is going on a bungee jump. She weighs 65 kg. The rope is 11m. In total, she fell 36 m. The first 11 m is free fall, and another 25m is simple harmonic motion. 1) k of rope 2)max spped 3)what point when she has max speed 4)amplitude of rope 5)how long does it take Homework...

Hi! I need to know what's the "hard bremsstrahlung emission". I googled it but it only showed papers (and few because my university don't have access to many) on experiences that at some point mention this effect but don't explain it. I know what's bremsstrahlung emission, just don't know...

hard circuit problem! help please! I need help with question number 4. The problem and relevant equations are attached. I= Current flow in Amperes V= voltage in volts The Attempt at a Solution I found the effective resistane (4.4 ohm) However, I could not find I3 or V5 I thought to...

Goal: You want to train your Senior Manager. He needs skills: x1, x2, x3, x4, x5, x6, x7, x8, x9, x10. You are to choose from the following programs/courses that fulfills all the senior manager's skill needs at the cheapest cost. p1 has x1, x3, x4 at $500 p2 has x3, x5, x9, x10 at $1000...

By what tools can we evaluate limits like this: Lim (sin((n+1)/n^2) + sin((n+2)/n^2) + ... + sin((2n)/n^2)) as n->infinity I've played around with Maclaurin polynomials, squeeze and Stolz–Cesàro theorems...

Homework Statement find the Laurent series for \frac{z+2}{z^{5}-8z^{2}} in 2<|z|<\infty Homework Equations The Attempt at a Solution Well, I factored out z^{5} in the denominator, which left me with a geometric sum (since |z|>2). I've come up with...

I have derived the following equation for the velocity of a collapsing shell of a collapsing star. \frac{dr}{dt}=-[GM(\frac{1}{2}-\frac{1}{R})]1/2 I now need to integrate this to find the free-fall time, and the hint is to manipulate the equation into a form where you can use a standard...

Homework Statement The 3m plank shown in section has a density of 800 kg/m3 and is hinged about a horizontal axis though its upper edge O. Calculate the angle theta assumed by the plank with the horizontal for the level of fresh water shown. Homework Equations Whats wrong with the editor...

2 electrons in box, "hard" walls, total energy E. Say we place 2 electrons inside an empty 1m cubed box with very "hard" walls, the electrons can penetrate only a very small distance into the walls of the box. Let us say that any photons produced by the scattering of the two electrons stay in...

I can't exess files from my specfic login only the public files e.g. files that were on my desktop. Any ideas? Cheers

What are Hard QCD processes ?

nm i got it figured out.

What is sum n=1 to infinity n^2/(n^4+1)

Okay here goes, I've read different things online about charging a capacitor so I just want to clear this up once and for all. When you are charging a capacitor, I always understood it as the electrons shifting from the wire connected to the negative end of the battery onto the plate, and the...

[PLAIN]http://folk.ntnu.no/jonvegar/images/math.gif I really need some help here (no program is allowed :smile:)

I know its not impossible, since us humans are cable of self healing to diseases and viruses why not operating systems? I know if there's a good AI program embedded in windows maybe can be used to search for abnormalities in its everyday operation and when found it will develop or create a file...

Homework Statement Is the statement true or sometimes false. Justify your answer: The determinant of a matrix is unchanged if the columns are written in reverse order. Homework Equations The Attempt at a Solution I understand that the only thing that is changed is the sign...

Homework Statement The diagram below illustrates the ballistic flight of circus daredevil, The Great Zacchini, over three ferris wheels, each 21.2 m high. Zacchini is launched at a speed of 27.6 m/s from the muzzle of the human cannon at an angle of 56.7 ° to the horizontal from a height of...

Hi, I need to calculate \Gamma(7/3)/\Gamma(1/3) is there some trick to doing this type of problem? I'm finding it really hard to do from first principles. Any help would be great, thanks!

Homework Statement A shell is fired with a muzzle velocity of 350ms/s at a target 1000m away. Calculate two angles at which the shell can be fired . Homework Equations I think these equations might help... v=u+at s=ut+1/2at^2 v^2=u^2 + 2as Hope these eqations are right. The...

Is there a function f , differentiable for all real x, such that | f (x) |< 2 and f (x)f ′ (x) ≥ sin(x)? I noticed that [f(x)*f(x)]' = 2f(x)*f'(x) = [f(x)]^2 So I tried multiplying that inequality by 2. 2f (x)f ′ (x) ≥ 2sin(x) Then I tried integrating both sides. [f(x)]^2 ≥...

Homework Statement A hydrogen atom is placed in a uniform electric field E(t) given by E(t) = Enaught*exp(-a*t) (where a is a constant) for t >0. The atom is initially in the ground state. What is the probability that, as t→∞ , the atom makes a transition to the 2p state? I know...

Homework Statement Prove that \int\sqrt{}9-x^2 dx =\frac{9\Theta}{2}+\frac{9sin2\Theta}{4}+c given that x=3sin\Theta Homework Equations The Attempt at a Solution \int\sqrt{}9-x^2 dx =\frac{(9-x^2)^{1.5}}{10x} =\frac{(-x^2)(\sqrt{-x^2+9}+9\sqrt{(-x^2)+9}}{10x}...

Hard intergral! :cry:If y = ke-x(sin2x), prove that \frac{d^2y}{dx^2} + 2\frac{dy}{dx} + 5y = 0:cry: Need help asap, No clue how to figure it out. teacher is away until next term, test next week.

I've seen this exact question in a book. (This is not homework) I've always thought this is because work has nothing to do with effort, but seeing this question on a book quite shocked me actually, is there any deeper explanation?

I have 4 p.c.s with SeaGate Barracuda ST3250310AS 250 GB Hard Disks installed in them . These pc.s have 2.7GHz AMD Athalon 64 X2 CPUs & Asus M2N68-AM SE2 Mobos . There is 2 GB DDR2 RAM installed in each of these machines (not dual-channeled) . They also have XFX GeForce 8400GS Cards . However...

I've got two calculus proofs that I can't seem to get! I was wondering if you guys could help me out a bit... 1. Homework Statement Suppose x_{n} is the sequence defined recursively by x_{1}=0 and x_{n+1}=\sqrt{5 + 2x_{n}} for n=0, 1, 2, 3, ... Prove that x_{n} converges and find...

1. Homework Statement [/b] \int e^{3x}\sqrt{1+e^{2x}dx Homework Equations Substitution Parts of Integration The Attempt at a Solution Started off using U substitution setting ex = to u. Then tried to use parts of integration. Now I am stuck.

Say compared to UCLA or Harvard, or compared to Cal State Northridge? And... Is California Polytechnic University, San Luis Obispo a UC or a CSU?

Hello, I am thinking of applying for the above course and just trying to gauge how difficult it is really. I have a 2:1 in physics from Cambridge, and although at times I felt like I was knocking my head against a brick wall overall I think I might have pulled to a first if the exams had...

I'm trying to understand why tennis balls have a higher bounce on clay courts than on hard courts. I understand that the amount of friction is greater on clay so as to slow the ball's vertical speed down and create a steeper angle of reflection. But I don't see how that explains why the...

My course is supposed to go from basic vector algebra to extrema, curl and divergence, (stopping before multiple integration) I don't need any help on this assignment I am just wondering how hard it looks compared to everything else. http://tinypic.com/r/2ly29u8/6

Homework Statement There's a cylindrical conductor of radius d, whose linear charge density is \lambda which is situated at a distance D from a infinite conductor plane. 1)Calculate the potential in the region that starts from the plane and ends at infinity (hence the cylindrical conductor...

Homework Statement (Take g = 10 m/s2 in this question.) The ends of a light inextensible string, of length 0.7 m, are attached to two fixed points A and B at the same horizontal level, where AQ = 0.4 m and QB = 0.1 m. A particle of mass 0.2 kg is attached to the string at the point P, where...

Hi How do you solve this equations analyticaly without solving a 4th degree polynomial sqrt(x)+y=11; x+sqrt(y)=7 Thanks