What is Section: Definition and 733 Discussions

Hey guys, I was just doing some mechanics of solids. I haven't done this section at uni yet, had holidays so was just trying to go ahead a bit. But the problem is I am completely lost on shear centre. If you could help me on a question, i'd be very grateful. Homework Statement The question is...

Homework Statement a) Find the reactions provided by the foundations at A and B. b) Use the method of Resolution at the Joints to calculate the forces in all the members. c) Which member will fail first and why ? Homework Equations ƩFx = 0 ƩFy = 0 ƩM = 0 The Attempt at a...

I was going to post this in the homework section, but I wasn't a hundred percent sure where it would fit. I'm writing a paper over the 1893 World's Fair and the battle between Edison and Tesla/Westinghouse after the fair. I'm doing my orienting before I delve into my thesis statement and I'm a...

I do not understand the interpretation of the http://hyperphysics.phy-astr.gsu.edu/hbase/rutsca.html" . To me, that equation says: (1) for a given θ, the proportion of particles exiting at θ does NOT depend on mass or charge; (2) if you integrated over all possible scattering angles, you...

why convergent rather than divergent? is this to maintain the constant air velocity. Can someone explain this better to me. Would be helpfull

The probability that one 3 foot section of wire is defective is 0.002. If someone has 450 feet of wire then what is the probability they will have 3 or more 3 feet sections that are defective?

I am replacing an exisitng solid rod with a new rod with a rod made from a different material and a different cross section. The new material has a MOE that varies with skin depth which is making it hard for me to develop an expression for stiffness (EI). The new rod has a hollow...

Homework Statement Long steam pipes often have a section in the shape of a \bigcup. Why?Homework Equations None.The Attempt at a Solution I'm at a loss. It might be because of some sort of volume expansion, but I'm not entirely sure why...

Hallo Physics Forum, this is my first post, so please be gentle to me :). I am currently studying the relativistic photoionization process, and especially its differential cross section. Let us assume that we have a highly energetic, unpolarized photon beam traveling on the z-axis and...

Rhodium has been measured and the following values have been obtained for the resonance parameters of a well-isolated resonance Eo=1.26 ev , σo=5000 b , Γ = 0.156 ev , σs=5.5 b , Is there anyone can help me HOW to calculate the thermal absorption cross section ? I'm disparate I don't know how to...

Can anyone please suggest me good texts for conic section, which contain both good theoretical explanation and problems?

Homework Statement The base region of a solid is bounded by y=x, y=(x-1)^2, and x = 1. The cross sections are semicircles perpendicular to the x-axis. Write a riemann sum and definite integral. Homework Equations The Attempt at a Solution First, I wrote down the formula...

I want to have a section title to the effect of "Pseudocode for the Func1 Function," but I would like "Func1" to be in typewriter font to indicate that I'm referencing programming code. Is there any good way to do this? The verbatim and verb commands don't seem to work. Thanks.

I'm having trouble understanding what David Griffith did in equation [1.25]. In this section he's trying to prove that psi stays normalized and I'm following him from [1.21] to [1.25] and where I'm getting stuck is understanding how: ∂/∂t|ψ|^2= i\hbar/2m(ψ*∂²/∂x²[ψ]-∂²/∂x²[ψ*]ψ)...

Homework Statement Red and green laser (wavelength of 650 nm and 532 nm respectively) are directed towards each other at 20 degrees. Each laser has 5 mW power, with diameter of 1mm. Assuming the intensity of the beams are decreased by 10% each after the 'collision', estimate the upper...

I'm currently starting a large comp-astro project, and trying to understand a bit of the background about heading of Hydrogen and Helium IGM clouds I am a bit confused about the the actual heating process. From the standard photoelectric effect, frequency has to pass a certain frequency (or...

Homework Statement Using conductivity constant (q=1.45*10^6mA) deduce the cross-Sectional area of the wire from the slope of the Data found in the graph. Voltage was kept constant 1.00 volts The wires are each 1m long After graphing the data the Current(mA) # of parralel lines 121.4...

Recently, I had lab. In the lab we took different objects and measured their strain. One object had a varying cross section. The data for strain was recorded. Right now, I'm trying to make a stress strain graph, but the problem is my equation for stress. I don't know how i can take my moment of...

Dear everyone, Recently i attend a course and my homework in below. As I have leave school for ten years, lots of knowledge have forgotten, so pls help me resolve it. Sincerely thanks your help. The midship section is subjected to a moment of Mxx = 80,000 tm Hogging. The idealized...

f is continues in [0,1] and differentiable in (0,1) f(0)=0 and for x\in(0,1) |f'(x)|<=|f(x)| and 0<a<1 prove: (i)the set {|f(x)| : 0<=x<=a} has maximum (ii)for every x\in(0,a] this innequality holds \frac{f(x)}{x}\leq max{|f(x)|:0<=x<=a} (iii)f(x)=0 for x\in[0,a] (iiiן)f(x)=0 for...

Homework Statement When it comes to evaluating integrals, there are two ways you can do it. First, you know that the integration of a function is the area under a curve, as shown in the left hand diagram. However, if you are looking over a narrow range along the x-axis, you can make an...

Homework Statement Prove that 0.493948<\int_0^{1/2} \frac{1}{1+x^4} dx<0.493958Homework Equations This chapter is about Taylor Polynomials, and specifically this section deals with Taylor's formula with remainder: f(x)=\sum_{k=0}^n \frac{f^{(k)}(a)}{k!} (x-a)^k + E_n(x) The general formula for...

from what I know: cross section in particles physics can be seen as throwing random darts on ballons on a wall, ie the wall is stationary. but if I want to work out the cross section of two laser beams at certain angles, the analogy above wouldn't hold would it? Since photons can never to...

Homework Statement \int\frac{\sqrt{2-x-x^2}}{x^2}dx Hint: multiply the numerator and denominator by \sqrt{2-x-x^2} Homework Equations This is in the Integration using Partial Fractions section, but the last few have not been using Partial Fractions. The Attempt at a Solution...

Homework Statement \int\frac{4x^5-1}{(x^5+x+1)^2}dx Homework Equations This is in the section on Partial Fractions. The main idea in this section was that you get the integral down to a sum integrals of the following forms: \int\frac{dx}{(x+a)^n} , \int \frac{x dx}{(x^2 + bx + c)^m} ...

Homework Statement Given that \frac{d}{dx} (\text{arccot}{x}-\arctan{1/x})=0 \hspace{10mm} \forall x \ne 0, prove that there is no constant C such that \text{arccot}{x}-\arctan{\frac{1}{x}}=C \hspace{10mm} \forall x \ne 0 and explain why this does not contradict the zero-derivative theorem...

Hi there, How can I find out how many photons would land in each areas, for the following patterns: http://www.bbk.ac.uk/tpru/BasilHiley/QuantEraserLight.pdf - page two's image (screen B) How many photons make up 'eraser no photon' pattern, and where each is. Likewise for the 'eraser yes...

In particle physics, what is a differential cross section? I think I understand what a cross section is, but I can't find any information on what a differential cross section is. I don't see how a cross section could be differentiated.

hi i am currently looking for a derivation of the differential cross section, that is not an abuse of mathematics, cause all derivation i found use differentials that are treated like fractions and so on? greetings Gavroy

Does anyone know why if (i) -1 < λ/μ < 0 then P is outside AB and nearer to A; (ii) λ/μ < -1 then P is outside AB and nearer to B? Can anybody give me the proof? Thanks in advance! Additional information: AP:PB = λ:μ

Hi everybody: I can see that there are formulas to calculate the moment of inertia of a 2D Area (Second moment of area) here: http://en.wikipedia.org/wiki/Second_moment_of_area" In the same link, there is a formula to calculate the Inertia moments about a ROTATED AXIS (Axis Rotation)...

Hello everyone. I have natural gas (methane) flowing through some piping, and the last little part of pipe is where I'm concerned. The gas goes through a drawn aluminum tube, about 5.08 mm ID (it's a very small tube). The tube has three 90 degree bends where it ejects out of an orifice. It...

So I have been reading about the cross section of neutron capture and have been reading about how the cross section for neutrons in a given material depends on neutron energy, the most important factor obviously. But I have not seen as much information on how, for a neutron of a given thermal...

Homework Statement The Femur bone in the human leg has a minimum effective cross section of about 3.0 cm2 How much compressible force can it withstand before breaking Homework Equations Compressive Strength (bone)(N/m2) = 170 x 106 P = F/A The Attempt at a Solution Not sure what a...

Hello Everyone, I have a fairly simple wind tunnel question but I cannot seem to connect the pieces. Homework Statement Consider a low speed one-circuit wind tunnel with an inlet to throat ratio of 12. The pressure difference between the inlet and the test section was measured to be 10...

Homework Statement base of a solid is bounded by y=\sqrt{x}, the x-axis, and x=9. each cross-section perpendicular to the x-axis is a semi-circle. find the volume of the solid Homework Equations The Attempt at a Solution I found the answer to be 81\pi/16 by the following steps...

Have any of you used the newly formatted, Section VIII Div., 2 yet? I have been using it for a while and noticed some things in it are just strange. Any thoughts? Thanks Matt

Homework Statement Hi everyone, I am now studying the Flyback converter as a component in a SMPS, my question is on the transformer unit on the converter. There are Primary side and Secondary side in the converter, at any given moment only either of the sides conducts, that is, when...

Homework Statement describe the conic section. a) 2X² - Y² - 4xy - 4X - 8Y + 14 = 0 convert to standard form of a conic section and identify its graph. b) X² + Y² - 2XY + 16X + 16Y = 0 Homework Equations a) 2X² - Y² - 4xy = 4X + 8Y - 14 b) X² + Y² - 2XY = -16X - 16Y aX²...

Hi. I am looking for some help calculating a cross section to derive the frequency of reaction in the early universe. The reaction taking place is: \nu_e + n \longleftrightarrow p + e^- After some calculation I came here: n_\nu \langle \sigma v \rangle = \frac {(2\pi)} {8 m^2}...

hello. I'm trying to get better acquainted with\LaTeX\ but I'm having some issues with document hierarchy. I've set LaTeX to automatically indent subsections by 1 inch, subsubsections by 2 in, etc. This way progressive sections "funnel" down the right side of the page. I've already done the...

steel floor beams span 7.0m and are at 4.2m spacing. the beams are fully laterally restrained by precast concrete floor slabs, 180mm thick, which they support. the floor has to support a speciified imposed load of 5.0 kNm-2. determine a suitable grade S275 steel universal beam section...

Homework Statement answer this question you need to create a Maple function using Maple's arrow (->) notation. Your function should take a Maple list of complex numbers as its argument and return the largest modulus from that list. Enter your function in the box below. N/A Homework...

Homework Statement This is the third problem of a project for a Calculus II course. My issue is with graphing. Below is the problem, and below that my tutors explanation via e-mail to try and help me. I understand everything thus far, except for how I go about graphing. I am not strong in...

hi guys, I was wondering what is the equation of cross section between fuselage and wing of the below airplanes:antonov 140 , B-707 , cessna-210 , cessna citation. Can anyone help?a book or a refrence or whatever you have

hi guys, I was wondering what is the equation of cross section between fuselage and wing of the below airplanes:antonov 140 , B-707 , cessna-210 , cessna citation. Can anyone help?a book or a refrence or whatever you have

Homework Statement What target thickness d is necessary to ensure that 1 % of all protons with a laboratory momentum of 10 GeV interact in a C12 – target? Homework Equations I have found af formula that states cross section = N_Reac/(N_beam * N_A * ro*d/M) Where N_Reac is the...

How we can prove (using geomtry and not differential equation) that the orbit of planet have to be a conic section.

Hi everybody, I have a experimental question. In cross-section calculation of production of particles (say D), one counts the number of produced D. To selection the D one has to apply some kinematic cuts. If cuts are tight, number of D will be less and if cuts are loose, number of D will be...

Hey, The hard cross-section of a 2 to 2 inelastic scattering goes as 1/E^2, where E is the center of mass energy. However, the cross-section in proton proton collisions increases with energy. My question is; does anybody have a good explanation for this and/or a good reference where I can...