Section Definition and 680 Threads

Help! Vectors! Homework Statement In the triangle ABC, D divides AB in the ratio 3:2, E divides DC in the ratio 1:5 and F divides AC in the ratio 1:2. Show (using position vectors and the section formula) that B, E and F are collinear and find BE:EF Homework Equations Section...

Please Help! Easy conic section question! 1. Graph each equation. Identify the conic section and its lines of symmetry. Then find the domain and range. 2. x^2 - y^2 - 9 = 0 3. I have no idea how to do this. I know it's a hyperbola because i solved for "y" and graphed it in my...

Hi I have an m-file which accesses another m-file at some point, but I don't want it to run the entire file. Is there a way to skip the first and last 10 lines of the file? I could just create a new file with the code I need, but this is like an addon to a programme, so if I could leave the...

Homework Statement a rectangular box with no top is formed by cutting out equal squares from the corners of a square sheet of metal, 10 cm by 10cm, and bending up the 4 sides. What size of square must be removed from each corner to generate a box with a volume of 50cm^3? (Note: there are 2...

Hello all, How to find deflections at force acting points in a non-uniform beam?. Please look at the figure. Thank you. Best regards

Hi guys, I am trying to calculate the section modulus of some channel section. I was going to use the value provided on the data sheet but its confusing me because it has values of section modulus in the X and Y axis. Am i right in assuming that i use section mod value where the load is...

Hi.. I've got a problem about moment inertia. I don't understand about looking the distance of centroid (y). I am still confucing about the formula of "y" in Moment Inertia. Can you shows me about the formula of y or if any thread for this before, I am glad to see it too.Thanx's for your help...

Hello, how do the angular distributions of Bhabha Scattering e^+ e^- \Rightarrow e^+ e^- and Muon pair production e+ e- \Rightarrow \mu^+ \mu^- differ? Regards, Phileas Fogg

Homework Statement I have attached a figure showing beam bending around 2 axis. I need to calculate section modulus Sx and Sy but seem to be getting the major and minor axis confused. I guess the problem comes in when I go to select which term is squared in my equation below. Homework...

Hello Ive come across some approximate cross section formulas during a course of particle physics. And in a reaction like A + B --> R --> C + D the cross section should be something like \sigma = K\frac{\Gamma_R^{AB}\Gamma_R^{CD}}{(s-m_R^2)^2+m_R^2\Gamma_R^2} Where K is a constant (depending...

Hi, I've been stuck on this for a few days now. I am trying to determine the X and Y axis of the general conic section equation: Q(x,y)=Ax^2 +Bxy+Cy^2 +Dx+ Ey+F =0 I have A, B, C, D, E, and F. I have already determined the center coordinates, but I have not found information on...

Well I'm supposed to draw Thomson cross section in polar plot by MATLAB software. Have I done it right? I mean does this figure that I got seem to be in polar plot or not? t = 0:.01:2*pi; r = 2.8179e-13 x = t,0.5*power(r,2)*(1+power(cos(t),2)) polar(t,x) Thanks

Please visit this http://www.mathhelpforum.com/math-help/calculus/61981-volume-toroidal-section.html".

So here's a crazy question...I was trying to think it through and have come up with nothing. Is it possible to bend a laser beam's cross section? For instance, if you are using a diode bar (which has a beam cross section resembling a line) is there a simple way to bend it into a...

I cannot figure out why the area of a section of a sphere used for integration is: (r * dtheta) (r * sin(theta) * dphi) ? where dtheta and dphi are the differential angles that subtend the arcs, which make up the sides of the rectangle used for the differential area. I did an...

How to determine the darcy friction factor for irregular cross section tunnels hi, I needed to calculate the f value for tunnels with these cross section area but I am not sure what are method available to calculate these shapes. Two of those cross section areas are already provided as...

A rectangular concrete-lined channel is 2m wide with Manning's n 0.012 and a bed slope of 0.0025 m/m. Obtain the depth of flow when the discharge is 9m^3/s. Q=V.A I have the discharge but how do I calculate the velocity without the area ?? Once I have the velocity I should be able to work it...

Hi, I'm trying to find a formula to help me find either the Moment of Inertia for a cruciform (rectangular cross) or better yet, its Section Modulus (S). Please see attached image.

Does anyone know anywhere where I can find reliable up-to-date cross section infromation? In particular I'm looking for the absorption cross section of Gadolinium-157 for thermal neutrons. Everywhere I look seems to give a different value ranging fro 70000barns up to 450000barns.

Prove or disprove: The intersection of the plane x+y+z=1 and the cylinder x^2+y^2=1 is an ellipse.

why is the cross section of photon - proton less than the electron- photon cross section for the same photon energy??

Is there a difference between (1-\gamma^5) and (1-\gamma_5) ? I see the two used interchangeably when calculating cross section.

Homework Statement http://img132.imageshack.us/img132/8958/mechanicsgv3.jpg The Attempt at a Solution (i) Is the weight balanced on both sides in a situation like this, in which case it would be: Or are the weights not equal and infact I am meant to work it out with dimensions in...

Cross section means the effective size of a nucleus for capturing a neutron, am I right? But what makes the cross sections for different nucleus different? I am a bit puzzled, why the cross section for Boron(for example) is so high?

I need to use this libraries with confidence. Any articles that involves benchmarking of these cross sections?

Hi all, I'm trying to teach myself high energy physics and was wondering if anyone knew a good reference site on calculating cross sections. I'm specifically trying to calculate the cross section for \nu _{\mu} + e^- \rightarrow \mu ^- + \nu_e using the 4-fermi interaction. Are there any good...

Problem Determine the differential and total cross sections for scattering from a "hard sphere" of radius R ("hard" means impenetrable). Relevant Formulae \sigma (\Omega) d \Omega = \frac{number \ of \ particles \ scattered \ into \ solid \ angle \ per \ unit \ time}{incident \ intensity}...

Hi! I just want to ask you, what is the principle of finding section between two vector subspaces. Let's say: U={(a,b,0) | a, b \in R} and W={(a,b,c) | a+b+c=0, a,b,c \in R} U, W are vector subspaces from R\stackrel{3}{}. P.S this is not homework question, just example, for my better...

What does it mean when they say s wave cross section, p wave cross section .. ?

Homework Statement Sorry wrong section! should be in calculus! does this problem converge or diverge? Homework Equations The Attempt at a Solution Not sure where to start, I've never seen a series arctan problem before, is there a way to switch it around to look like i want...

Homework Statement I've been asked to find the cross section of a hydrogen atom in thermal equalibrum at 6000K for a photon which induces a transition from the ground state to the first excited state. The density of states for n=2 is 4x the density of states for n=1 i.e. g(E2) = 4*g(E1)...

Homework Statement On page 221 Zwiebach uses the "definition" M^2 = -p^2. I am not sure where this comes from since normally m^2c^4 + p^2 c^2 = E^2 and even dropping the c's does not reduce to that. EDIT: I see. It is the light-cone Lorentz generator of section 11.6. How is he getting the...

I'm extracting data from a Monte Carlo sim. and i need to extract the differential cross-sections of the resultant protons and neutrons in momentum and rapidity space. ie \frac{d\sigma}{dy} ; \frac{d\sigma}{dp} and \frac{d^2\sigma}{dydp} where I know the values of y and p...

I'm writing a paper on Thorium utilization in nuclear reactors. In this connection I'm looking for figures which describe the neutron capture and neutron fission cross sections over a wide energy range (not only thermal). There are probably some online resources unbeknown to me, any hints?

I have a hyperbola with the following equation and I am trying to find my angles to eventually rotate this (conic section), but I don't know what to do because when I follow the standard form of (A-C)/B, I get zero. Is there some trick that I don't know about. x^2+4xy+y^2=12

I'm calculating an ionization cross section in partially ionized plasma, with taking into account of correlation effects. I'm trying to do it with help of variation phase method. Please, help me to find some link to useful articles.

Three Section Telescopic Driveshaft? I have two gearboxes I need to connect. In operation they will move laterally in relation to each other. They move in one plane only (no offset or angular movement). The present setup just uses a two part driveshave with a U-Joint at each end to allow for...

Are we allowed to bring a calculator in the test? If yes, which kind of calculators do they allow/prohibit?

Figure shows the cross section of a single cell, thin walled beam with the horizontal axis of symmetry. The direct stresses are carried by the booms B1 to B4, while the walls are effective only in carrying shear stresses. Assuming that the basic theory of bending is applicable, calculate the...

I have already tried some internet searches and looked through and solved the more interesting exercises in two of my Larson & Hostetler college algebra/precalculus books, and some in an intermediate algebra book - but I wish I could find many more useful, practical and applied exercises for...

"Universe" section of NASA http://science.hq.nasa.gov/missions/universe.html NASA Science Missions Directorate used to have a division they called "Astrophysics". According to Steinn's blog (Dynamics of Cats) they renamed it the Universe division...

Hello, I'm having problems with the following question: Neutral metal sphere A, of mass 0.10 kg, hangs from an insulating wire 2.0 m long. An identical metal sphere B, with charge -q, is brought into contact with sphere A. The spheres repel and settle as shown. Calculate the initial Charge on...

I'm about to draw shear and moment diagram in 2D, and I wonder if there are any general rules as where to section for instance this ski? http://www.badongo.com/pic/504635

I would like to know if an equation exists for the volume of a section of a cone. For example, a conic shaped tank lying on its side with the point to the left and the circular base to the right is filled partially with liquid. The height of the liquid, volume of the cone, length of the cone...

Having seen the horrors of long times between posts, and the starving databanks ready for more information, I am officially moving to the astronomy section. My experience may be questioned, but I can assure you that I do know a lot about Space in general, even though my AstroPhysics is...

[b]1. picture of problem: http://img.photobucket.com/albums/v223/lilaznbabe/4_56.gif (a) What minimum force F is needed to lift the piano (mass M) using the pulley apparatus shown in Fig. 4-56? (Enter your answers in terms of some multiple of Mg.) ____ Mg (I got .5) (b) Determine the tension...

Homework Statement The total cross section of a S wave is given by the following equation Sigma=(pi/k)*(b^2)/((E-En)^2+(b/2)^2)) prove that b is the width of the resonance. Homework Equations Nothing that is the only thing The Attempt at a Solution I already solved the question...

For my diploma thesis I must provide a calculation that reproduces the results given on page 46 of the paper hep-ph/0309342 . For those who do not want to look it up, I briefly explain what it is about: It concerns the two-body scattering processes (1) N + V => L + H, (2) N + L => V + H, (3) N...

In a scattering experiment, an aluminium foil of thickness L = 10E-6 m is placed in a beam of intensity of 6E12 particles per second. The differential scattering crosss section is known to be of the form. \frac{d\sigma}{d\Omega} = A + Bcos^2 (\theta) where \theta is the...

If I show something that a cross section is proportional to: 1 / (16p^2 sin^4( x) + 8mpsin^2 (x) + m^2) does it imply that the cross section is proportional to 1 / sin^4 (x) as well?