Approach Definition and 565 Threads

Homework Statement \lim_{x \to 1} \frac {\int^{x}_{1} \frac{1}{t} dt} {\int^{x}_{1} \frac {1}{(2t+1)}dt} Homework Equations The Attempt at a Solution I am not really sure how I am suppose to approach this problem, I would think that as x approaches 1 the integrals will...

Henderson gives a good talk. He's been working with Abhay Ashtekar on reformulating loop cosmology as a spinfoam-like path integral---also using GFT (group field theory) where a parameter shows up that may have physical interest (possible connection with the cosmological constant). He got...

I'm studying for a test. The question is: Let A be the straight line segment from -3-4i to 4+3i. Let B be the arc of the circle |z| = 5 going anti-clockwise from -3-4i to 4+3i. Let C be the arc of the circle |z| = 5 going anti-clockwise from -3-i to 4+3i. Define: IA = \int_A 1/z dz IB =...

Here's my solution to the problem of finding the distance of closest approach for two atoms approaching each other in a Lennard-Jones potential, starting with velocities (+/-) v_0: They start with energy T0 = (1/2)m(2v02) which is conserved. Thus, E = T + V = (1/2)m(2v2) + A/r12 - B/r6 = T0...

Here is another approach to finding the volume : Let x_{1} be a point in [x.x+Δx] such that : f(x_{1}) = minimum value of f(x) in [x,x+Δx] Let x_{2} be a point in [x,x+Δx] such that : f(x_{2}) = maximum value of f(x) in [x,x+Δx] Then, \pi.[f(x_{1})]^2.\Delta x\leq\Delta...

Hi. I recently graduated with a B.A. in Political Science. I've been accepted into a pretty decent law school and could head my life in that very comfortable and secure direction. However I've always had a passion for physics, I spend so much of my free time reading about it, watching online...

Hello everyone, I am interested in Tigh-Binding calculation of energy dispersion for non-crystalline material. I am familiar with usual tight-binding approach for periodic structure, but I don’t understand how to use it in case of disordered system, For example cluster (or quantum dot) with...

Hello everyone, I am a first year student taking electrical engineering. I have a midterm coming up on Friday on circuit analysis. I get the concept of it but what I am wondering is what is your approach when you have to do reduce and return to analyze a circuit? I am looking for a...

Homework Statement I have potential hole from a to b. This potential hole is sum of U(r) (bounded function) and l(l+1)/r^2, where l is azimuthal quantum number. In my book about semiclassical approach is written: if n_{r} >>1 then in rules of quantization in basic range of integration...

Homework Statement For many years the level or protein in foodstuffs including meat, dairy and cereals has been carried out using the Kjeldahl method. This involves conversion of any nitrogenous compounds to ammonia by boiling the sample of food in concentrated sulfuric acid followed by...

Find the mass of one turn of wire in the form of a helix with a linear density e^(-z) in lbs/ft. Would I write as <e^(-z)*cost,e^(-z)*sint, t>? Maybe?

Allow me to explain my new theory, The "Mancini conjecture." Ok...lets say I have an integral like (4-x^2)^(1/2) dx. and letting u = 4-x^2, we get du/dx = -2x, and if I took the second derivative of du/dx...i would get -2 this would be ideal, because I would then have du'' = -2 dx, or -1/2...

NASA Scientists Plan to Approach Girl by 2018. Film at 11 (or right below) http://www.theonion.com/content/video/nasa_scientists_plan_to_approach?utm_source=slate_rss_1 Best of all, her eyes are the color of Magnesium Iron Silicate.

I have the following two problems and I don't know how to approach them. We talked about payoffs, Simple and Compound Growth,Conditional Probability, Law of total probability, Baye's Theorem. Simple math is obviously not enough, I need to prove it using those topics we covered. I'm not...

The algebraic formulation of quantum mechanics (and related stuff, like quantum thermodynamics & dynamical systems etc.) via C*-algebras provides a viewpoint based mostly on abstract functional analysis. However, I've yet to see a working application of this approach, i.e. an example of a...

Homework Statement An alpha particle 4 2 He 2+ approaches a stationary gold nucleus 197 79 Au at a speed of 7.0 X 10^6 ms-1. By considering only electrostatic repulsion, calculate the closest possible distance of apporach between the alpha particle and gold nucleus. Homework Equations -The...

I am curious about the how Newton discovered his laws of motion and his law of universal gravitation. It seems in modern education, the laws are introduced to students somewhat 'magically', and then the students then do various practical experiments and calculations to verify them. If we step...

Has anyone worked out a functional Parametric chart that enables one to choose a appropriate Microscope (exclude Scanning electron MicroScopes(MS)) amongst the multitude of choices for a modern academic micro-biological & research lab, hence formulated a general guideline? The MS should feature...

Homework Statement Given the momentum p1 and p2, find the distance of closest approach (b) also known as the impact parameter. I think we are also given charges q because I later have written solve for b2 in terms of x2, q2, P2, p\bulletx, q\bulletx, and p\bulletq. [those are supposed to be dot...

Homework Statement I have a problem that says: Find the directional derivative of C(x, y) in the radial direction at any surface point (x, y). It then says: Find the shark’s approach path from any point (x0, y0) at the sea surface. I found the directional derivative in the radial...

Homework Statement Use the determinate method and also the Guass elimination method to find the inverse of the following matrix. Check your results by direct multiplication A =\left | \begin{array}{ccc} 2&1&0\\ 1&0&0\\ 4&1&2 \end{array}\right | = Let's do...

Hi everybody: does anyone know of a good book on special relativity that takes a geometric approach? I'm doing research that requires that I know special relativity, and, while working problems out for personal-practice, all I do is either: 1) make gamma-messes 2) clumsily-use invariants...

Homework Statement Show that the natural numbers satisfy commutativity of multiplication and distributivity of multiplication over addition. Homework Equations The Attempt at a Solution I'm wondering if there is any potential circularity in this reasoning. I proved distributivity...

There are a couple of fantastic e-books on probability and random processes, designed for graduate electrical engineering classes but should be interesting to many other folks as well. The first is from prof. Hajek at Illinois. http://www.ifp.illinois.edu/~hajek/Papers/randomprocesses.html...

I tried to use Lagrangian and Hamiltonian to solve 1-D elastic collision, but I got nothing but constant velocity motion. Is it because I miss some constraint? Such as the motion is colinear or something?But how to write a constraint like colinear? Or it's not actually solvable with Hamiltonian...

What is the analog of particle creation and vacuum energy in the Bohmian approach? Has Bohmian QFT been developed to a point where it can provide a satisfactory explanation of this phenomenon within it's framework?

Homework Statement ^^I'm sort of lost as to how to approach this question. Should i just find the voltage at node A? Then at B? But what confuses me the most are these time values we need to take into account. So what would be the best way to approach this question? Thanks.

calculate \iint_{M}^{}\vec{F}\vec{dS} where \vec{F}=(e^y,ye^x,x^2y) M is a part of hyperboloid x^2+y^2 which is located at 0<=x<=1 and 0<=y<=1 ,and its normal vector points outside like this : http://i28.tinypic.com/f9p63r.gif i am used to solve it like this...

Hey, all. What would be some good books on continuum mechanics for undergraduates majoring in Physics? I'm familiar with Timoshenko's book that's used in Engineering, but I'm looking for something a Physics student may use. Thanks in advance.

Homework Statement Deep Space Nine sees Enterprise and a shuttle approach from exactly opposite directions with 0.6 c and 0.4 c, respectively. At what fraction of the speed of light (b) does Enterprise see the shuttle approach? Homework Equations V2=(v1+ v1,2)/[1 +(v1*v1,2/c^2)] The...

Hi there, i would like everyone to evaluate my working here, this is my attempt to wave equation / vibrating system using vector approach. please correct me if i had made some mistakes. Your help is much appreciated, Thanks, and have a nice day. :smile: Regards, Daniel.

First of all, I searched the forums and couldn't really find one on how to approach a quadratic equation that has brackets. Here is the equation: y=(x+1)2 - 2 My teacher told me to factorize by sight in pairs and i used this equation for it: ax2+bx+c. I think c=-2 but I don't know how to get...

Suppose I want to show that an+1 < an one could find the derivative of the sequence and then show that it is negative for a certain domain of values for x. However is it also possible to conclusively prove that an+1 < an simply by subbing in n+1 and n and show that the inequality leads to a...

Hey, I'm in my Physics 1 course now, and am having issues. I've done well in math, and will be entering Calculus 3 next semester. I usually have no issues doing calculations at all. The problem I seem to be having is with physics problems in general. Sometimes I have to derive a totally new...

Is somebody here involved with the causal set approach to QG? http://arxiv.org/abs/gr-qc/0309009 is a nice introduction to the theme, and I liked among the introduction with some quotes of Riemann. If so or any of the good people like to give opinion, I would like to make some questions...

I can't figure out how to use the Green's function approach rigorously, i.e., taking into account the fact that the Dirac Delta function is not a function on the reals. Suppose we have Laplace's Equation: \nabla^2 \phi(\vec{x})=f(\vec{x}) The solution, for "well-behaved" f(\vec{x}) is...

Well we know what matryoshka dolls are? Those nested dolls one inside another. I am a mere laymen and amateur that's why I am using descriptive terms instead of math rigor. So what should the approach be: If RH nest Hilbert-Polya conjecture, then what things nest HP conjecture? And ad...

I've been trying to start teaching myself Calculus recently out of interest and the amount of useful info on PF is awesome but I can't seem to find a good way to actually start it off. As far as books are concerned, it seems that Stewart's is the standard but supposedly it's too watered down...

Homework Statement I need to find N: {[pi^(N+1)] / (N+1)!} . {1/2^N} <= 10^-5 Homework Equations The Attempt at a Solution I'm really struggling with this, i think taking logs is involved, but i can't seem to find a value of N. Any help?

I'm taking a class in abstract algebra this summer, so I thought I'd get ahead by reading the book before class starts. This is from a book called "Abstract Algebra: A Geometric Approach", chapter 1: Applying the Principle of Mathematical Induction with a slight modification. If S' \subset \{n...

Homework Statement http://img245.imageshack.us/img245/7535/38187200.th.jpg I need to find F from the picture above Homework Equations The Attempt at a Solution My answer so far is: \frac{-y}{(x^2+y^2)} \vec{i} + \frac{x}{(x^2+y^2)} \vec{j} is this correct?

Homework Statement Assume that a point source of light gives 3 watt = 3 J/s of light energy. a) assume uniform radiation in all dirrections, find the light intensity in ev/m2*s b)Assuming some reasonable size for an atom, **** the energy/time incident on the atom for this intensity.Homework...

Hi everyone, I have a question for anyone who considers themselves adept at designing circuits. I was wondering, how do you approach the design of complicated circuits? What stages do you go through to get from a concept to a real working circuit? I myself am not an electrical engineer...

Anyone know a nifty change of variables or trigonometric identity that will make this integral relatively easy to do: \int_0^T \sin(at+b) \cos(ct+d) dt 'Cause from where I'm standing, that's pretty awful... Thanks!

Homework Statement I am supposed to evaluate the integral using partial fractions. \int \frac{1}{(x+5)^2(x-1)} dx 2. The attempt at a solution So after doing all the work, I get (-1/36)ln|x+5| - (13/6)ln|x+5| + (1/36)ln|x-1| But the answer in the book appears as (-1/36)ln|x+5| -...

Homework Statement I am having trouble remembering how to uncouple these. Homework Equations \frac{dt}{ds}=1 \frac{du}{ds}=2tu The Attempt at a Solution I remember putting it into a matrix. x'=\lambda x

Homework Statement Sove cosz=2 Homework Equations The Attempt at a Solution I need to solve this, but am not quite sure how. I was told to use log.

Homework Statement Two forces, F1 and F2, act at a point. F1 has a magnitude of 8.60 N and is directed at an angle of 63.0 (DEGREES) above the negative x-axis in the second quadrant. F2 has a magnitude of 6.00 N and is directed at an angle of 53.2 (DEGREES) below the negative x-axis in the...

Homework Statement Two protons are moving directly toward one another. When they are very far apart, their initial speeds are 3.00*10^6 m/s. What is the distance of closest approach? Homework Equations The Attempt at a Solution I really need help in question. I need to know how to...

... as the sun was traveleing at a closer distance towards the Earth , would Earth bound objects start to fly away from the Earth surface and head towards the sun's surface , or would everything on Earth surface fly towards the sun's surface as the same time the Earth itself flew towards the...