Section Definition and 680 Threads

Hello Everyone, I am after an expression for the torsion stiffness constant of a rectangular hollow section (RHS) with varying wall thickness. I have done some research into finding an expression that allows for four varying wall thicknesses but have not found anything as of yet. The only...

Lagrangian I have is little bit massy so I don't write in here. Like in ψψ(dagger) , or ψ∅ -> ψ∅, How can I calculate the differential cross section or total, or amplitudes?

Homework Statement Asymptotes at y=±\sqrt{10} x /5 Foci: (±\sqrt{7},0)Homework Equations The Attempt at a Solution It's obviously a hyperbola. What I can't wrap my head around is why a^2 + b^2 ≠ c^2 c = sqrt 7 ; correct? This yields 7=25+10 obviously NOT true. What am I missing here?

I'm learning scattering theory from Griffiths' book, and I don't really understand the meaning of differential cross section; it's one of those things that I find hard to conceptualize and give a physical meaning to. The most intuitive description he gives is "the proportionality factor between...

Hello, I've found in some of the articles on experimental quantum physics the term "Topological cross section" Now I'm trying to understand what is it and in particular what the difference between topological and differential cross section? Thanks in advance for suggestions on any reading...

I have completed bending moment and shear force diagrams and have a question asking for the mean shear stress. I know this is worked out using the formula: tau = F/A. I am unsure of what force to use is it the max shear force on my diagram? My other thought is that it could be an avergae of...

Homework Statement Let k>0 be such that (x^2-x)+k(y^2-y)=0 defines an ellipse with focal length equal to 2 . If (p,q) are the coordinates of a point in the ellipse with q^2 - q\not=0 , then what is \frac{p-p^2}{q^2-q} ? Homework Equations The fact that the sum of the distances from...

qq- --->qq- differential cross section and mandelstam variables Homework Statement for the problem statement please look the attachement Homework Equations The problem is asking to express the mandelstam variables in temrs of the scattering angle θ.I would like to ask the quastion...

Hi, I'm reading an article called SuperSymmetric Dark Matter, by G. Jungman et al. doi:10.1016/0370-1573(95)00058-5 and in section 3.2, he claims that <σv> ≈ \alpha^{2}(100 GeV)^{-2} \approx10^{-25} cm^{3} s^{-1},[\itex] for \alpha \approx \frac{1}{100}. When I run through the calculation...

Hey all, so i finished logarithms a few weeks ago for mathematics/precalculus 12( also known as algebra II in the states i think ) and i got 100% on the test but don't feel i understand logs very much... i understand how to solve problems and the laws completely but i started reading a book...

Homework Statement Hi everyone this is my first post. I am having a problem with the bending moments of the beam (see attached files). I cannot for the life of me seem to get the bending moment to finish at 0 so I can draw the bending moment diagram. I know this is generally quite a simple...

hello , can anyone give the formula of the differential cross section and the macro cross section because in each web i see a different notation thank you

Consider the cross section of two beams of same material as shown in the file attached. The area moment of inertia I about the central axis is equal for both the c/s. I have calculated it. Can somebody explain why the second c/s (2 in the figure ) is preferred for the design?

Need to find sketch of "Coronal section thru the posterior frontal lobe..." ? Hey everyone, I need to find a sketch of the following: "Coronal section through the posterior frontal lobe to reveal basal ganglis lateral to the diencephalon" ?? Having a tough time finding one. This...

Homework Statement Find σ , the differential cross section, starting from the expression below and integrating over solid angle Ω Homework Equations dσ/dΩ = r2sin2θ The Attempt at a Solution dσ = r2sin2θ dΩ I remember that dΩ = sinθ dθ dμ and doing the μ integral from 0...

I wish to verify a couple of assertions. From the NNDC and other references, it appears that the neutron capture cross section of 3H (Tritium) is zero to a first approximation. This holds true for all neutron energies, including cold neutrons. These statements are equivalent to asserting that 4H...

...in the elastic region? Or does the x section area decrease only after the yield point?

Hi guys, I am working on a Fortran code for a while. Might seem ridiculous but to better trace it, I split code into three separate parts and trying to compile both using the command 'ifort ss.f singpot.f SNGPOT.f -o ss'. With this command I receive the error singpot.f(22): error #6236: A...

'Ello, I have a question regarding the results in this paper (and another which I will mention later) http://arxiv.org/abs/hep-ph/0212199 Now, I'm not so concerned about the 'braney' bit, but more their definition of the cross section in Eqn. (46). They have included the usual (2j+1)...

Hello, currently I work on 2->3 scattering process. So there exist five external momenta and in my case 5 different Feynman diagrams, for which I have already calculated the full matrix element. The matrix element is a function of various scalar products of the four-momenta. This scattering...

Homework Statement Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis. Homework Equations y = \sqrt{x-1} , y = 0, x = 5; about y = 3 The Attempt at a Solution I already completed graphing it, but not really sure how...

Can quantum computers simulate quantum effects and non quantum effects in one program? If not will they be able to in the future? Can a classical computer simulate quantum mechanics?

Homework Statement A beam has a solid square cross section of 100mm and is simply supported by two supports 3m apart. Calculate the dead load that can be safely supported when applied to the middle of the beam. Homework Equations Solid square cross section of beam: 100mm Material...

the higher the energy of the photon, the more powerful it can ionize an atom but why then the absorption cross section decreases with the photon energy?

a basic problem but i have no idea how to measure it

Hello. I was hoping someone could help me understand some units. In several papers, I have seen the two photon LIF signal written as: S = n*(Ω/4π)*T*G*σ*(E/hv)^2*η*a where the units are n (density of measured atom): #/cm3 Ω/4π (solid angle fraction): unitless T (optical transmission...

Rao: Topology: Proposition 1.2.4. If (X,T) is a topological space, a subset A of X is closed iff the the derived set of A is a subset of A: A'\subseteq A. Rao's proof of (A'\subseteq A) \Rightarrow (X\setminus A \in T) goes like this: To me, this looks like enough to show that...

where can I buy a nuclear power plant section plan? Thank you !

Homework Statement The only given data is that the cross section is 1m^2, the shape is circular (like a cut wire/rod) and i have to find the volume. Homework Equations from what I've searched, i found the equation: but i have no idea what to do with it, i still haven't learned it at...

Homework Statement What is the volume if the area bounded by y=x^2 and y=9 and the cross sections are perpendicular to the y axis Homework Equations The Attempt at a Solution I have no idea

As you all know the NEC code permits only 42 circuits per panel. so what we could do if we need more than 42 circuits ? In order to use more than 42 circuits we can add new section panel. However my question is do we need a separate feeder and breaker for the additional section?

I'm just wondering what the difference is between a cross section and a scattering cross section? Or is there any? I can't seem to find anywhere that clears it up, in fact there's a whole section on scattering cross sections in Kibble and Berkshire but they don't define it once :P

I am reading chapter three of Huang's Statistical Mechanics and I have a problem with equation (3.22). Having discussed the derivation of the classical cross section for a scattering process, Huang moves on to the quantum version of it. He states that in quantum mechanics the fundamental...

Dear all Apart from cost saving (or reduction in material)what is the technical advantage using I section instead of square section? My application is,section is going to be simply supported to the static load.myself awared that I section is good for bending loads.Instead i am using square...

Homework Statement Identify the type of conic section whose equation is given as y^2+2y=4x^2+3 Also find its vertices and foci (y-k)^2/a^2-(x-h)^2/b^2=1 Homework Equations I believe when you have x&y ^2 in an equation it can be either an ellipse or a hyperbola but if the signs are...

is there a simple way to determine the section modulus of a member made of a W and WT shape welded together, one on top of another about the x-axis. the steel manual has the properties for the individual sections; would the section modulus of each be able to be added together or will i have to...

what is the cross section area of the water?? Homework Statement Determine an expression for the cross sectional area A of the fluid in the tank as a function of D and H. Homework Equations A=pi*r2 The Attempt at a Solution i try to let the radius equal to the height but then the...

hey guys i have a question. i solved the problem but i don't understand how to do it. Two perpendicular straight wires join in the ends of a semicircular loop of radius a = 11 cm, as shown in the figure above. If the current I =6 A, what is the resultant field at the center of the circular...

Hi all. This is my first time in the Physics Forums. I would like to ask for guidance in a calculation of a cross section of a process. I know the Feynman graph but I'm completely lost on how to start the calculation.. For example.. p p -> Z -> μμ Many thanks in advance..

Homework Statement When is the magnetic flux on a section of a closed surface equal to zero? A. When the magnetic field is in the direction opposite that of the section’s area vector. B. When the magnetic field is in the direction of the section’s area vector. C. When the magnetic field...

Homework Statement Which describes the magnetic flux through a section of a loop? A. It is a vector that is directed outward through the section. B. It is a vector that is directed inward through the section. C It is a vector that is tangent to the section. D. It is a scalar...

I recently saw the Evaluated Nuclear Data File provided by Brookhaven national lab., where in i saw the plot of "Neutron Energy Vs cross section (total)" for different elements. http://www.nndc.bnl.gov/sigma/index.jsp?as=1&lib=endfb7.0&nsub=10 Now what i am interested in is, can we derive or...

Is it possible to only show section numbers without chapter numbers in a LaTeX document of class "book"? For instance, Munkres' Topology text breaks things down into chapters but the sections are numbered independent of the chapter. For instance, Sections 1-11 are in Chapter 1, 12-22 in Chapter...

Hi there, I currently trying to calculate the second moment of area of an L shaped cross section. The reason for this is I have carried out a buckling experiment on a strut of this cross section and want to calculate some theoretical results to compare to my experimental results. I need the...

New here, sorry if I'm in the wrong place or unclear, etc. I've been looking at torsion on solid plates and the torsion constant. I was wondering how to handle the torsion constant on a plate of changing cross section (e.g. there are holes drilled in it, changing the area of the cross section...

Given the general equation of conic section: Ax2+Bxy+Cy2+Dx+Ey+F=0 How can we find the type of conic section from the above equation? I've used method of rotating coodinate around the origin (from Oxy to Ox'y', Ox' makes an angle θ to Ox, counterclockwise) such that the symmetry axes of the...

Here is the problem Let A be an infinite subset of \(\mathbb{R} \) that is bounded above and let \( u= \mbox{sup }A \). Show that there exists an increasing sequence \( (x_n) \)with \( x_n\in A\) for all \(n\in\mathbb{N} \) such that \(u=\lim (x_n)\). My try. Since A is infinite, it means...

here is the problem. Let \( a>0\) and \( z_1 > 0\) . define \( z_{n+1}=\sqrt{a+z_n} \) for all \( n\in \mathbb{N} \). Show that \( (z_n) \) converges and find the limit. I am supposed to use monotone convergence theorem. For that I need to prove that the sequence is bounded and monotone. I can...

Homework Statement DT fusion produces 14.1 MeV neutrons. A diagnostic for a total fusion yield is the Cu-63( n, 2n)Cu-62 reaction. A) what is the threshold for this reaction? Cu-63 also undergoes a radiative capture reaction yielding Cu-64. This reaction has a thermal cross section of 4.5b...

here is the problem from Bartle's book Let \( X=(x_n) \) be a sequence of positive real numbers such that \( \mbox{lim }(x_{n+1}/x_n) = L > 1 \). Show that \( X \) is not bounded sequence and hence is not convergent. I am using negation of the goal. So I assumed that the sequence is bounded...