Term Definition and 742 Threads

I am a bit confused over the frequency term that appears in Johnson and Shot noise formulae. What is this term? Is it bandwidth? Of what? In relation to say a photodiode, is it the range of frequencies being detected? And how would this relate to say a DC circuit which no frequency terms...

Homework Statement Find the coefficient on the x^2 term in ∫[(x+9)/3] * [log(x+1)] * dx Answer: -1/12 Homework Equations Integration by parts ∫dv * u = u * v - ∫du * v The Attempt at a Solution 1. I integrated by parts to get ------------------------- ∫[(x+9)/3] * [log(x+1)] * dx] =...

In layman's terms: what does the term "in layman's terms" mean? Please explain that to me. Everyone is using it and I don't get it. It bugs me so much I can't sleep.

Homework Statement Calculate the smallest angle (in degrees) that the total angular momentum of an atom in a 7D term can make with the z-axis. Homework Equations 2S+1LJ The Attempt at a Solution Given that the total angular momentum of the atom is defined by the quantum number J...

Homework Statement Find the general term of the sequence, starting with n=1, determine whether the sequence converges, and if so find its limit. (a) {(1/2), (3/4), (5/6), (7/8), ...} (b) {(1-(1/2), ((1/3)-(1/2)), ((1/3)-(1/4)), ((1/5)-(1/4)),...} Homework Equations My text only...

This has got to, for all time, define the term "clueless". North Americans of my generation will get it right away; I'm not sure about the rest of you. For maximum effect, watch right until the end, because that's where the punchline is delivered by Larry himself...

What is a finite-difference discretization for the partial differential term: \frac{\partial^4\phi}{\partial x^2\partial y^2} Thanks in advance.

Hey!, I was repeating for myself a course I had from a earlier year, fluid mechanics. I looked at the derivation of the navier stokes equations, and there is one term that does not give meaning to me. Take a look at the x-momentum equation here...

My answer is: it is the relationship between the angle of incidence and the angle of refraction. Is it correct? If not, what should be the correct answer?

Hi everyone, Im in my third year of studying chemical engineering. Its been ALoT of work so far, but its always been manageable and I've been able pass every class so far and I have a pretty good gpa (3.5). However, this current term is really killing me. I dedicate every waking moment...

term "ground" mean in an ELECTRONIC circuit? What does the term "ground" mean in an ELECTRONIC circuit? A bus strip usually contains two columns: one for GROUND and one for a supply voltage. What does ground mean in this context and how do we ground a circuit while using a breadboard?

Homework Statement (For power series about x=1) Using the error formula, show that \left|ln(1.5)-p_{3}(1.5)\right|\leq\frac{(0.5)^{4}}{4} Homework Equations p_{3}(x) = x-1 - \frac{(x-1)^{2}}{2} + \frac{(x-1)^{3}}{3} \\\epsilon_{n}(x)=\frac{f^{n+1}(\xi)}{(n+1)!}(x-x_{o})^{n+1}\\where \xi lies...

I'm not very fund of the subject, but what i know is that the Schwarzschild metric and other known solutions for Einstein's action have some constant representing mass. However, I encountered some solutions where no such constant existed. Can someone explain to me what does this mean exactly? In...

I've tried and failed to search for this on the forum, so apologies if this has been answered many times before. Given a variable u which is a function of x and y: u = u\left(x,y\right)\\ is it possible to solve the pde: Au_{xx} + 2Bu_{xy} + Cu_{yy} = D\\ The knowns are: The real...

What exactly are Magnetars? I've heard the term used before, and all I remember about them are that they have very powerful magnetic fields. What are they? How do they form and how do we detect them?

2 issues. 1. I don't know what this is called. unicode or something? allow me to explain. I opened a notepad. Typed something in Korean and saved it long time ago. Now I switched regional settings to Japanese. I opened the notepad I saved long time ago and the text is now shown in Japanese...

I am trying to prove two things equal that involves a bunch of dot products, cross products and curls. I can't remember the exact problem, but this demonstrates my question.My question is the left side \delta/\deltax*(UxVx + UyVy + UzVz) The right side is \delta/\deltax*(VxUx + VyUy + VzUz +...

Hello, Here is the Boltzmann collision term as it is expressed on http://en.wikipedia.org/wiki/Boltzmann_equation" : Deriving the H theorem from this equation is the way to usually prove of the irreversibility of this term. Of course, this collision term should not be symmetric by...

I took the first term of a Foundations of Physics sequence (251) last year, and understood most of the material fairly well. It was calculus based Newtonian mechanics; units and vectors; one-dimensional motion; Newton’s laws; work and energy; momentum and collisions. Since it's been a year...

The evidence commonly presented for the formation of life (Fl term of Drake equation) 1.Life formed virtually as soon as possible on Earth (when conditions were suitable) It implies that life is easy to form when we have the right conditions [Does the Rapid Appearance of Life on Earth Suggest...

Hi, I'm reading Quantum Field Theory in a Nutshell by A. Zee, which is excellent but it is occasionally difficult to fill in the blanks on one's own. Once such place is the integration of the Hopf term, which results from integrating out the gauge field in a Lagrangian with a Chern-Simons...

Homework Statement Hi, I need your help in my homework. My Instructor asked that question? Why there is not a work term in entropy balance equation? Homework Equations The Attempt at a Solution I have researched about it and I found that, entropy has not an exact physical...

Hey everyone I just started an engineering course and have been given a few questions but I am struggling with this one as i feel that i have not included all the info that should be there. Can someone tell me briefly what they would explain the term permittivity as and how they think it would...

Is it possible to calculate the energy of a state from an atomic term symbol? Or are we only able to use the lande inteval rule to find spin orbit interaction splittings?

Homework Statement Consider the following waves: \vec E _1 (\vec r , t) =\vec E_1 (\vec r) e^{-i \omega t} and \vec E _2 (\vec r , t) =\vec E_2 (\vec r) e^{-i \omega t} where the form of the wavefront isn't specified and where \vec E_1 and \vec E_2 are complex vectors which depend on spatial...

Homework Statement \int_{0}^{b} \int_{0}^{2\pi} C_{k,m}(r)^2 \left{\begin{array}{cc}cos(m\theta)^2\\sin(m\theta)^2 \end{array}\right} r dr d\theta Homework Equations See above The Attempt at a Solution Ignoring the 'r' integral for a second, the solution that I see written...

An interesting sideline about Galilean relativity is the following. Up to that time the perennial question was, what kept a body moving? Galileo realized that this was the wrong question, since uniform motion in a straight line is not an absolute concept. The right question is, what keeps a body...

The ground state electron configuration of Carbon atom is 1s^{2}2s^{2}2p^{2} For the electrons, 1s^{2}2s^{2}, L=0, S=0 So only consider electrons of 2p^{2}, and s_{1}=s_{2}=1/2 ---> S=0,1 l_{1}=l_{2}=1 ---> L=0,1,2 For S=0, L=0; J=0, so we have ^{1}S_{0} For S=0, L=1; J=1, so...

a1=22+32+62 a2=32+42+122 a3=52+52+202 Using these, gIve a general term for an such that an is always a perfect square

Homework Statement Assume all sn =/= 0, and that the limit L = lim|(sn+1)/(sn)| exist. a) Show that if L<1 then lim sn = 0 b) Show that if L>1 then lim sn = + oo Homework Equations There is a hint that we should select 'a' s.t. L<a<1 and obtain N s.t. n>N => |sn+1 < a|sn|. Then show that...

by simplifying the denominator, 1/3 + 4/3^5 + 9/3^7 + 16/3^9 Cant find the nth term. i am assuming there is something wrong with the given. i suppose 1/3 should be 1/3^3. If so, then the nth term is n^2/3^(2n+1) thanks.. :)

Hello forum, I am trying to solve a differential equation for the last four hours and I can't figure out how... here it is \frac{d^2x(t)}{dt^2} + \frac{dx(t)}{dt} + c x(t) = d e^{-a t^2} actually my problem is how to handle the Gaussian term... if anyone can help please...

Homework Statement Is this statement correct? If the nth term of a sequence is a quadratic expression in n, then the sequence is an A.P. Homework Equations The Attempt at a Solution Take arbitrary t(n)=n^2-2n-2 I substituted 1,2,3 in the above expression and noted the c.d...

if we consider fluid flow, then bernoulis equation says that pressure must reduce when velocity is high.What is the direction of pressure when fluid is in flow? When fluid is stationary then pressure varies in vertical direction. It acts in downward direction on account of gravity. Means it is...

I am not an expert in math, but as an electronics tech we use sinewaves all the time. I understand how it is derived from a circle well enough ( a phasor rotating about a circle). And that makes sense as that is how electricity can be generated due to the orientation of the generator...

Why the term "diffraction" in XRD When there is selective reflection of x-rays from crystals, why the phenomena is called "diffraction"? As we know that diffraction is associated with the bending of waves at the corners of any obstacle, here there does not seem to be any bending around the...

I know I probably learned this 10 years ago, but I really have no idea how to simplify something like this: (A*B + C*D + E*F)2 Is there any kind of shortcut (even a website that does it automatically!) that can help me solve expressions like this?

Homework Statement e3x(3sin x-cos x) The Attempt at a Solution e3x3(3sin x-cos x)+(3cos x+sin x)e3x=10e3xsin x. Is that right?

Hi, I'm reading the SU(N) chapter in Jones' Group theory book. In SU(3) we have these 3 component spinors which transform as \psi^{'}_{a}=U_{a}^{..b}\psi_{b} and we have upper spinors defined by \psi^{a}=\epsilon^{abc}\phi_{[bc]} Now if consider building up higher-dimensional reps, by taking...

PSI is a relative scalar field of weight w in the sense that it transforms between the hatted and unhatted coordinate systems according to, \bar{\psi}=J^{w}\psiWhere J is the jacobian. According to the book, the ordinary partial derivative of a relative scalar field is not a relative tensor...

Dear all, This question might sound trivial but for weeks I am unsure about the correct answer: 1. Given there is a radiator. The radiator's performance is stated in [Watt]. 2. Given there is a nuclear plant. The plant's performance is also stated in [Watt]. Is it correct English to...

I have a problem understanding the effect of source terms in qft. I am interested in understanding how a static point source will interact with a massless field. Let me consider a simple example of a linear chain of masses coupled by some springs. In the continuum limit, the Lagrangian...

What is the term for phobia of becoming mother? Please let me know.

I read somewhere that the term for a concept that we don't try to define is "primitive". Primitives are supposed to be to definitions what axioms are to theorems. I also read that when one of these deliberately undefined concepts is explained (but not really defined) by a description in plain...

Hello In the following integral which I obtained from Wolfram, what is the physical meaning (e.g. in a heat conduction problem) of \sqrt{-\sinh^{2}(bx)}. Also how to evaluate this at x=L. Thanks...

There seems to be a trend to misuse the term model, particularly by non scientists such as educationalists, business and politicians. Should we be worried as the non scientific version means the diametric opposite.

Hello, I am interested in the electronic states of the N2 molecule. Now it is a homonuclear diatomic molecule and http://en.wikipedia.org/wiki/Molecular_term_symbol" ) but I do not understand what the Latin letters before the molecular term symbols mean. Here are some of the states X^{1}...

Hey! My teacher told me that there is a correction term to Newtons law of gravitation when you take general relativity into account, somthing lik: F=G\frac{M_1M_2}{r^2}+F_{correction} I been searching like mad but can't find it on the internet anywhere. The only things I found was a set of...

Is there a term for the vertical elongation of a planet? This would be the angular distance above the horizon that a planet appears at the instant the sun sets, or in mathematical terms it would be: x=elongation theta=angle between the ecliptic and the horizon "vertical elongation" = x *...

Hey everyone, I know, lots of threads and online information about Gaussian integrals. But still, I couldn't find what I am looking for: Is there a general formula for the integral \int_{\mathbb{R}^d} d^d y \left|\vec{y}\right| \exp(-\alpha \vec{y}^2) where y is a vector of arbitrary...