Terms Definition and 1000 Threads

line integral -- confusion on squares and square root terms Homework Statement Do you see where they have sqrt(16 sin^2t etc = 5? How do they get that, the answer should be 7, the square root of 16 is 4, sin^2 + cos^2 is 1 and the square root of 9 is 3, 3 + 4 = 7. It's like they're...

Homework Statement Find the derivative of (x^2)(sinx)(tanx) Homework Equations f(x+y)(d/dx)=(x)(y)d/dx+(y)(x)d/dx That's for differentiating with 2 terms. With 3, I haven't done it yet. The Attempt at a Solution x^2(sinx)(sec^2x)+tanx(sinx)2x+x^2(tanx)(cosx)...

For expressions like: f(z) = (1+z2)/(1+z4) how does one write the modulus of that in terms of lzl?

Hi everyone, Say I have a 2D one loop integral of the form $$ I^s_n(\Delta)=\int d^2 l \frac{(l^2)^s}{(l^2-\Delta)^n} $$ Using that ##1 = \frac{1}{2} \partial_\mu l^\mu##, I can relate say $$I^1_2(\Delta)=I^0_1(\Delta)$$ + total derivative term. In dimensional regularization one usually...

Homework Statement Different numbers x, y and z are the first three terms of a geometric progression with common ratio r, and also the first, second and fourth terms of an arithmetic progression. a. Find the value of r. b. Find which term of the arithmetic progression will next be equal to...

Homework Statement Find an approximation of (0.99)5 using the first three terms of its expansion. 2. The attempt at a solution To get to the binomial theorem I divided 0.99 into (0.99)5 = (1-0.01)5 = {1+(-0.01)}5 Then, T1 = 5C0(1)5 = 1 x 1=1 T2 = 5C1(1)5-1(-0.01)1 = 5x1x...

Standard from book: v(t)=K1e^(s1t)+K2e^(s2t) Can I have this below instead? v(t)=K1e^s1 + K1e^s2 - K2e^s3 - K2e^s4 I'm really confused, I sometimes get this when I do calculations. Any ideas? Thanks!

Sorry if this is an obvious question...I understand how the justification via the pressure v temp graph works, but I'm not quite understanding freezing point depression in terms of intermolecular forces and temperature. I was taught that due to attractive IMF between solute and solvent particles...

Homework Statement ##u(\omega) d\omega \propto \frac{(\hbar \omega) (\omega^2)}{e^{\hbar \omega \over k_B T}-1} d \omega ##Homework Equations The Attempt at a Solution ##\hbar \omega ## is the energy of a photon ##\frac{1}{e^{\hbar \omega \over k_B T}-1} ##and this is the density of states...

Homework Statement Express the given vector in terms of its coordinates: The vector from the origin to the end point of the vector from (-3,7,2) in the direction and with the length of u = (2, -3, 4) The Attempt at a Solution I don't even know the algorithm for solving this...

hey guys i want to know the definition of these terms & what are they but please i don't want big words because i won't understand i want to understand it simply: 1-Fermi level 2-Density of states 3-Carrier concentration & the graphs (in the attachment) 4-Mass action law 5-Charge...

Can you please help me find which terms match these definitions: 1. Reflection from a smooth surface in which the angle of incidence equals the angle of reflection. 2. Imaginary line perpendicular to the surface and serves as a reference line for angular measurement. 3. Straight...

The terms "absolute" and "relative" In discussions about relativity I use the term "absolute" as a synonym for "frame invariant" and "relative" as a synonym for "frame variant". I went to look for an authoritative definition and could not find one, so I am a little concerned. Is my usage...

How would i write 1.047 rad in terms of pi? I know the answer i will get is Pi/3 rad, but HOW do i get this answer? I know how to convert degrees to radians and vice versa in terms of pi but this particular question is in radians. Help?

"If we have to take three terms in an AP, it is convenient ti take them as a-d,a,a+d. In general, we take a-rd,a-(r-1)d,...,a-d,a,a+d, in case we have to take (2r+1) terms in an AP." What do they mean by the portion in bold? What is 'r' here ?

Homework Statement Let \vec{R} = (t + \sin t) \hat{i} + (t + \cos t) \hat{j} denotes at time t the position of a moving particle. Determine the radial and circumferential components of acceleration as a function of t. Homework Equations v_r = \dot{r} v_{\theta} = r\dot{\theta}...

So I have read both of the following books Teach yourself physics http://www.amazon.com/dp/1444103091/?tag=pfamazon01-20 complete mathematics http://www.amazon.com/dp/1444105027/?tag=pfamazon01-20 Now I am not sure where to go from here. My goal is to have a firm understanding of...

Can someone please help me figure out which terms match these definitions for nuclear physics? 1. Process in which a nuclide is transformed into a nuclide of a different element. 2. Total number of nucleons remains constant. 3. A radioactive transformation of a nuclide in which a bound...

Homework Statement How many terms has the G.p whose 2nd term is 1/2 and common ratio and the last term 1/4 and 1/128 respectiveley? From the question, it can be deduced that the common ratio, r =1/4 and the last term = 1/128 Homework Equations The Nt term of a G.p = arn-1...

Hi All, My first post here. As far as I've understood there are problems with massless states in two dimensions. In the problem I am working on I have a 2D (non linear) sigma model with a lot of symmetries. The worldsheet fields come as heavy and massless. My main interest is to...

I'm currently studying experiments where one or more factors are random, i.e. random effects models. In this model a professor explained that the Expected Mean Square calculations for any factor are: Expected Mean Square (factor) = (lower level error terms) + (term relating to factor) For...

Without using ' opposite charges of matter' explanation as a foundation for defining anti-matter, I wonder if anyone can present a more direct definition and examples.

Hello, I need help trying to simplify the equation below, I believe it should be in terms of x and constants only, no trigonometry. "Simplify arctan(cot(x)), assuming 0<x<pi/2" After many attempted solutions and failures, my most recent attempt is below. let arctan(1/tanx) = u ==> tan...

Dear all, I have a quantum system made up of two layers. An electric field is applied with two voltages applied at both layers. I want to calculate the electronic densities that reside at the two laters in terms of the wavefunctions obtained from solving the HamiltoniaN..Anyone knows of an...

Homework Statement Find the expected value of cos(A+B) where A is a constant and B is a random variable with a pdf f(b). Present the answer in terms of f(b). The Attempt at a Solution I don't know how far I can go with the answer -- I have tried for a bit now to remove an integral with no...

Homework Statement Find Laplace transformation H(t-1)t^2Homework Equations The Attempt at a Solution [2(e^-s)f(t^2)]/s^3 I'm not sure how to get t^2 in terms of t-1 I know the answer is (2+2s+s^2)/s^3

Homework Statement The problem along with its detailed solution are attached. Homework Equations Inequality, infinite summation and improper integral. The Attempt at a Solution I'm following the solution but I can't justify the first (and only) less-than-or-equal sign. Why is that...

Hi, all I have been reading about copula, but still very confused. What exactly is a copula? My understanding is: there are couple of components 1. uniform cdf marginal 2. a covariance matrix What exactly is this thing? Why am I calculating the marginals and what does it have to do...

Hey everyone, This is a really strange question and I wasn't sure where to post it, but I need those who are well versed in physics and math to help with this. I recently started a new band and we came up with the symbol "1_" as our logo. We had a name, One Unknown, but we found out that it...

Homework Statement One of the problems in our test is this. Express the eigenvectors of J_y in terms of the eigenkets of J^2 and J_z . Homework Equations The Attempt at a Solution I know the matrix of J_y and the operators or eigenkets for J_y , J^2 and J_z . I just don't seem...

In the double slit experiment there are interference terms which are responsible for the way in which particles appear on a screen (diffraction pattern). The density matrix for an electron with spin |+X> going into a stern Gerlach alligned in the z direction also has off diagonal terms which...

A problem involving Force in terms of time? Homework Statement There is a body of 3 kg which is moving to the right with a velocity of 10 m/s. A force of 6 N/s2t2 is applied on the body to the left. How much distane will the body have traveled from t=0 when its velocity is 0 m/s...

Homework Statement The problem asks us to find the equation for an isotropic oscillator in the form of an equation for an ellipse. I'm in PHYS 212, Analytic Mechanics. Homework Equations x=Acost(ωt) y=5Acos(ωt-.6435) The equations I found for x and y. The Attempt at a...

Hello, I can't seem to find a reference formulating the Schrödinger equation as a set of two differential equations in terms of the modulus |\psi| and the phase S instead as one diff. eq. in terms of the complex wavefunction \psi = |\psi|e^{i S}. Can anyone show me the way?

Homework Statement The Gamma function is given by \Gamma(x) = 0∫∞ tx-1e-t dt Evaluate 0∫∞ exp(-αy2)dy in terms of Gamma functions. Homework Equations n/a The Attempt at a Solution Honestly, I don't know where to start. I have knowledge of parametric differentiation (we use...

Write f(x) in terms of the unit step function u(x). $u(x)=\left\{ \begin{array}{rcl} 1\ &\text{if}& \ x\geq 0 \\ 0\ &\text{if}& \ x<0\end{array} \right.$ $f(x)=\left\{ \begin{array}{rcl} 1\ &\text{if}& \ 2n\le x\le 2n+1 \\ 0\ &\text{elsewhere}\end{array} \right.$

Homework Statement x' ={{-1,1},{-4, 3}}*x, with x(0) = {{1},{1}} Solve the differential equation where x = {{x(t)}, {y(t)}} Homework Equations The Attempt at a Solution I have e^t*{{1},{-2}} + e^t*{{t},{2t+1}} but I'm not sure how to get it in terms of what it's asking.Edit: Please quick...

Homework Statement Which terms of this sequence add up to 1010100? (Don't need to be consecutive terms) {an}∞n=1 = {n(n+1)/2}∞n=1 Homework Equations The Attempt at a Solution The sequence is made up of the sums of all the numbers less than and including n. Don't really know much more...

According to wikipedia :- " Formally, temperature is defined as the derivative of the internal energy with respect to the entropy." I always thought entropy is defined in terms of energy and temperature. IS this true that temperature is defined in terms of entropy and energy? According...

Hello, I have two functions say f1(β) and f2(β) as follows: f1(β)=1/(aδ^2) + 1/(bδ) + O(1) ... (1) and f2(β)= c+dδ+O(δ^2) ... (2) where δ = β-η and a,b,c,d and η are constants. Eq. (1) and (2) are the Taylor series expansions of f1(β) and f2(β) about η...

Homework Statement The problem I am doing is problem 1.55 in Schroeders Intro to Thermal Physics. Unfortunately, I have to come here for help a lot because the office hourse are not until after the homework is due...In any case, the first part of the question was to show that the potential...

Reparametrize the curve R(t) in terms of arc length measured from the point where t = 0 R(t) is defined by x = et, y = \sqrt{2}t, z = -e-t Arc length S = ∫ ||R'(t)||dt ||R'(t)||= sqrt{\dot{x}2 + \dot{y}2 + \dot{z}2}The attempt at a solution Getting R'(t) ==> x = et, y = \sqrt{2}, z = e-t...

hi i am not a newbie to physics but some terms are quite confusing such as inertia, momentum and many other similar ones can anyone explain what actually the momentum is so that my concept become more clear about it.. thank you

Say we have a Lagrangian \mathcal{L}=\bar{u}i\kern+0.15em /\kern-0.65em Du+\bar{d}i\kern+0.15em /\kern-0.65em Dd-m_u\bar{u}u-m_d\bar{d}d, where u and d are fermions. In Peskin&Schroeder p. 667 it says that if m_u and m_d are very small, we can neglect the last two terms of the Lagrangian. I'd...

I think that buoyancy is caused by the increase of density with depth (the deeper you go, the more molecules there are per unit volume). Therefore an object in a fluid will be hit by more of the fluid molecules from below than from above (even if the difference is only a tiny fraction of 1%). Is...

Homework Statement Prove that the unit vector r{hat} of two-dimensional polar coordinates is equal to r{hat}= x{hat}cosθ + y{hat}sinθ and find the corresponding expression for θ{hat}. all I need is the last part... I'm just not sure what θ{hat} is? How do I go about doing this? Nothing in my...

Can someone explain how the Stark Effect works in Layman's terms? I'm trying to understand how an electric field can cool down atoms. What is the electric field doing exactly to the atoms? How is it lowering the atomic energy levels? Is there a difference between Stark Shifting and Stark...

I've been having a very difficult time understanding why band structure is expressed in terms of momentum/crystalline directions. I've included a picture of the band structure of silicon so that you can better understand my question. I think I understand basic crystalline structures and the...

Hi, I remember having read in basic calculus that the following is true, but I don't know what this property is called and am having a hard time finding a reference to this. d u(x,y) = \frac{\partial u}{\partial x} dx + \frac{\partial u}{\partial y} dy Ques: Is this true ? Is this true for...

Hi there, I apologise that I should probably know this/its a stupid question but I seem to have forgotten all physics over the holiday and so any help would be great! I have been told that there is a beam of atoms with spin quantum number 1/2 and zero orbital angular momentum, with spin +1/2...