Section Definition and 680 Threads

  1. S

    Semi-circle cross section volume

    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...
  2. CFDFEAGURU

    Have You Used the New ASME Section VIII Div. 2?

    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
  3. N

    The transformer section in Flyback converter

    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...
  4. D

    Exploring a Conic Section: 2X² - Y² - 4xy - 4X - 8Y + 14 = 0

    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...
  5. W

    LaTeX LaTeX end section or subsection

    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...
  6. T

    Selecting a Suitable S275 Steel Universal Beam Section

    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...
  7. I

    Calculus II Applied Project - Graphing Section - Help with Excel

    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...
  8. A

    Cross Section Equation of Antonov 140, B-707, Cessna-210 & Citation

    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
  9. A

    Airplane Fuselage-Wing Cross Section Equations and References

    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
  10. S

    Orbit of planet have to be a conic section

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

    How do Kinematic Cuts Affect Cross-Section Calculation?

    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...
  12. K

    Cross section energy dependence

    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...
  13. S

    Fortran Fortran: Pointer to array section with vector subscripts

    Hi. I'm trying to make a pointer point to sections of a rank-2 array given by specific values of it's second index. I other words: given a table I wan't a pointer to point to specific columns, making of it a "filtered" table. The method I was trying was like DOUBLE PRECISION...
  14. DaveC426913

    Can Online Community Members Be Sued for Libel Under Section 230?

    Wondering if anyone who has a passing understanding of the law would care to enlighten me about online libel law. Section 230 protects 3rd party content-providers from the claims of their users. What are implications upon an online community service whose /intent/ was to encourage...
  15. E

    Mean free path and collision cross section

    Homework Statement I do need to calculate the mean free path for an ion with a radius of 9 x 10‐8 cm in pressures of 10‐8 Torr, 10‐6 Torr, 10‐4 Torr and 10‐2 Torr Homework Equations There are different equations I found but the most one is λ= 1/Nσ N gas number density which I do not...
  16. A

    Differential cross section with invariant matrix element

    Homework Statement Calculate the differential cross section for A+B---> C+D with an invariant matrix element Homework Equations See attachment The Attempt at a Solution I have no idea how to even begin this problem. The course I am taking is an undergraduate course in intermediate modern...
  17. R

    Calculating size of rectangle cross section

    Homework Statement A cmedium carbon steel rod has a rectangular cross section and must cope with a tension of 29 430 Newtons . The thickness of the rod is 15 mm calculate the siz of the cross section? Homework Equations A=P/Ok [b]3. The Attempt at a Solution [/b O = UTS = 750...
  18. Rasalhague

    Arnold: ODEs, Ch. 1, section 2.2

    Attempting Problem 1 of Arnold: ODEs, Ch. 1, section 2.2, it seems I'm not understanding something pretty basic about what he means by "the solution of a differential equation". This is the kind of equation he's talking about: \dot{x} = \mathbf{v}(x) \enspace\enspace\enspace (1) where, if...
  19. A

    Double Integral over General Region : Hass Section 13.2 - Problem 5

    Homework Statement Outer Integral: From zero to one dy Inner Integral: from zero to y^2 dx Function is: 3y^3 * e^(xy) Homework Equations None The Attempt at a Solution Have tried numerous u substitutions on e^(xy), but taking me nowhere. I am clearly doing something wrong...
  20. M

    Fortran Fortran (better suited to programming section)

    The following question pertains to programming, but I have posted it here because I want the views of mathematicians (also of physicists and engineers), not those of computer scientists (which i already know) and I do not know how many of the former category care to look into programming...
  21. U

    A question about cutting the section to compute the shearing tension

    Hello Dears! I've just registered here. It sounds nice! :smile: As I've seen in different solution manuals here in my country, there are several realizations of how to cut the section we've got, to compute the resultant shearing tension of a shear loading. For instance, as you see in the...
  22. H

    Can I Calculate Traces and Cross Sections in QED Using Gamma Matrices?

    hi how to calculate the traces of product of Dirac matrices in QED. i want caculate crossection of process scattering in QED. a program to calculate it
  23. R

    SolidWorks FEA (Varying Cross Section)

    Does anyone know how SolidWorks calculates the stresses for this simulation. Can anyone give me an idea, is it second moment of area? y/r = m/i? Thanks Richard.
  24. H

    Nonvanishing section for direct sum of Mobius band

    For a direct sum of Mobius band, it is trivial if it has two linear independent nonvanishing sections. I have the following as my sections: s1=(E^(i*theta), (Cos(theta/2), Sin(theta/2)) s2=(E^(i*theta), (-Sin(theta/2), Cos(theta/2)) Clearly, the above sections are linearly independent and...
  25. F

    I don't know if this the wrong section, but

    I am just wondering, in all of my professor's office, they have a huge collection of textbooks. Did they purchase them or did the university provide the books for them. I am actually thinking of keeping some o mf textbooks and not selling them
  26. A

    Transfer matrix, section in Jan Smit's book on Lattice Fields theory

    Hi guys, Basically I'm working through Jan Smit's book, http://books.google.com/books?id=pFgUFfG7JygC&printsec=frontcover&dq=introduction+to+quantum+fields+on+a+lattice&hl=en&src=bmrr&ei=mabWTOjtMoK4hAfh0eGGBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDIQ6AEwAA#v=onepage&q&f=false , and I'm...
  27. A

    Using an integral to find area of section of a sphere

    Homework Statement (sorry i have not learned latex to display the maths) Integrating to find the proportion of the area of a sphere that is within the section described by the bounds of theta. theta is longitude axis angle -(pi)/9 <= theta <= pi/9 thi is lattitudal axis angle 0 <= thi <= 2...
  28. Z

    Method to find the centre of a conic section from its equation

    In the second degree equation of a conic section (ellipse/hyperbola), I have seen many books following this method to find out the centre of the conic section- 1) Differentiate the equation w.r.t x treating y as constant 2) Differentiate the equation w.r.t y treating x as constant. 3) Solve...
  29. M

    What is Stronger Steel Square Hollow Section or steel Circular Hollow Section

    Hey there, I am going to by building a chassis and i am wanting to find out if 33.7mm dia X 4mm thickness circular hollow section or 40mm X 40mm X 2.5mm Square Hollow Section is stronger these two weight around the same per meter thanks Ian
  30. D

    Photon interaction cross section? What?

    Photon interaction cross section? What?!? Hey guys-- I'm practicing for the GRE, and I came across a question that has stuff that's not even in my textbook! I haven't found much from googling either. Here is the question: My instinct was to guess (C) because graphs I had seen of the...
  31. E

    Wikipedia math section full of errors

    wikipedia is full of errors
  32. Z

    Deriving Formula for Radius of Conical Section at Height h

    Homework Statement Suppose there is a Conical section (of a right circular cone) of total height 'l' and radii 'a' and 'b' (a>b). How do we derive the formula for the radius at a height 'h' (h<l) ?Homework Equations The Attempt at a Solution
  33. G

    Design a tension member w/ cross section

    design a tension member w/ cross section... Homework Statement You are to design a tension member (square rod) with a cross section to carry a mass of 575 000 kg with a safety factor of 2 against yield and a safety factor of 3 against static fracture (overload). a) What is the design...
  34. S

    How to Solve Dot Product Homework Using Vector v?

    Homework Statement Homework Equations know dot product The Attempt at a Solution [SIZE="5"]PART A [SIZE="5"]PART B not sure what's it asking for help would be great
  35. E

    Getting Extinction cross section from Radar cross section using HFSS

    Hi, Has anyone tried using the HFSS software to get the extinction cross section of a particle? I've been told that the extinction cross section of a particle is the imaginary part of the radar cross section in forward direction, so I did exactly what the RCS tutorial from HFSS did, except...
  36. A

    Calculating minimum I-beam section area under load

    Homework Statement This seems to a reasonably basic question to go through but yet I seem to have a bit of a mental block on it. so any help in the right direction would be great.. An I-beam is 10mm thick on the web and flange, is 6m high and has a Young's modulus of 200 GN/m2. The design must...
  37. M

    LaTeX LaTeX Question (formating section headings)

    I would like to divide the body of my document into two columns. In the left column go the section headings and in the right column go the section text. My attempt is to make a new command: [FONT="Courier New"]\newdimen\sectionwidth \newdimen\resumewidth \sectionwidth=0.25 \textwidth...
  38. T

    How to Graph a Parabolic Equation Without a Calculator?

    What's the process that needs to take place to be able to graph the following equation (not-using a graphing calculator): x2 + 12xy + 36y2 + 2x - 3y - 9 = 0 I know to use the B2 - 4AC formula to identify the equation as being parabolic, though I don't understand the formula... Looking at...
  39. S

    Cross section data, how to fill in the gaps?

    I wanted information on the 18F production rates of 18O(p,n)18F compared to 20Ne(d,alpha)18F. I found a 1979 graph that showed some nice curves between 2.3 and 22 MeV but I wanted to see what things looked like between 1 MeV and 2.5 MeV. So I went here...
  40. A

    The prism is made from glass and its cross section is an

    Homework Statement the prism is made from glass, and its cross section is an equilateral triangle. the indices of refraction for the red and violet light are 1.662 and 1.698, respectively. the angle of incidence for both the red and violet light is 60 degrees. find the angles of refraction at...
  41. S

    Differential cross section formula of electron-positron pair production.

    Homework Statement I need to calculate the differential cross section in order of Mandelstam variable t, instead of the angle \theta. My problem is with the change of variable not the amplitude of the process. I'm getting a global minus sign which can only be wrong. It seems I'm making a very...
  42. T

    Flux attenuation, given interaction cross section

    It strikes me that this may well be fairly easy, but i can't quite get my head round the correct way to lay this problem out (at least in a mathematical sense). If you are considering a neutron flux onto a fully understood material, and you also know the neutron interaction cross section of...
  43. A

    ABAQUS 6.9 Meshed Beam Cross Section

    I need help with my beam structure in abaqus. The beams I need to model are hollow and elliptical. This is not included in abaqus' library or profiles. So I want to make a Meshed beam cross section as described in the manual. However, the manual is quite difficult to understand. Can someone...
  44. O

    Hi There is no structural/civil section Is structural/civil not highly regarded

    Hi! There is no structural/civil section! Is structural/civil not highly regarded in America? For you civils/structurals: What would you recommend as a good speciality in civil/structural engineering, and why? I'm not looking for the usual listings of specialities, but if anyone has any...
  45. A

    Volumes of Cross Sections with Perpendicular Planes

    Hey guys I am new here i was wondering if anyone can help me understand this problem better Homework Statement The base of a certain solid is the circle x^2 + y^2 = 9. Cross sections of the solid with planes perpendicular to the y-axis are semicircles with their diameter in the base of the...
  46. J

    Relationship between Beam Section Depth and Bending Moment

    Ok. There are 2 universal beams. One is 500mm deep and the other one is 400mm deep. For both beams, the top and bottom flanges are 200mm wide x 10mm deep. [SPAN of the beams is not given] Questions is..If the maximum bending moment capacity of the 400mm deep universal beam is 200 kn.m. What...
  47. M

    Compton Cross Section: Derivation & Relation

    What's the relation for the Compton cross section? I remember it going as 1/(1-cos(theta)) but can't remember the rest. I searched for a derivation but can't find one at the moment.
  48. S

    Stresses on Side Face of Channel Section Under Torque

    if there is a torque on a channel section twisting it axially what stresses do u expect to be on a side face..??
  49. S

    What Stresses Are Present on a Twisted Channel Section?

    if there is a torque on a channel section twisting it axially what stresses do u expect to be on the side face ??
  50. A

    Gradient descent, anything better than golden section line search

    Hi This is a long story, I make it short: I am working in a project where I need to find a matrix defined by a third degree polynomial, the solution can be found iteratively using a gradient descent technique, I am using the golden section line search already implemented in MATLAB (with the...
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