Beam Definition and 1000 Threads

Consider a light beam has a mechanism,say by some unknown virtual particles like tachyon or etc(like we use light beam to observe other things)...Or some mechanism to observe other light beam,then will the other beam of light move at speed of light for it too.? And also taking relativity...

Hi All, Protons repel each other and in order to make them collide in the LHC huge amounts of energy have to be put in place, my question is; if we launch a beam of electrons transversal to the beam of protons and right in the collision point of the protons, would not this increase the energy...

I just want to know the relationship between beam depth and column size. I know there is a relationship. But in uniform loading, do they increase beam depth or column size? or rather.. would increasing beam depth and keeping column constant be able to handle more load? or should the beam depth...

Hello everyone, I am an undergraduate student studying lasers. I have hard time to comprehend why does the beam diffract upon leaving the laser, does it have something to do with the wavefront being limited in size? Can you explain why does the following formula exists and how is it derived...

Homework Statement Dense No 1 grade of Douglas Fir-Larch, 6x12 is to be used as a simple beam spanning 10 feet with a 2 feet overhang. The beam has the loading shown in the sketch I've attached. Determine the maximum value of the concentrated load "P" to maintain the structural integrity...

Hi, I'm looking for a parameter or a design guideline that could say weather or not the classical bending theory can be applied to certain beam under certain load. I'm making my dissertation about some work on cantilever beam and it's first natural frequency, so in order to model correctly...

Hi there, first post on these forums. I have a seemingly simply question about beam bending. We (mechanical engineers) are all very familiar with the standard beam bending scenario. The beams are always shown being loaded perpendicular to the neutral axis, regardless of the type of support...

I've been reading through my mechanics of materials textbook recently, notably in regard to the section on the deflection of beams. The well regarded Euler-Bernoulli beam theory relates the radius of curvature for the beam to the internal bending moment and flexural rigidity. However the theory...

When two particle beams meet head on, more energy is available than when the particle beam is directed at a fixed target. Why is this??

Hi all, Actually I'm supposed to run and find results in google search. But that doesn't give any useful information, retrieves some nomenclatures which deals with estimation of technique or deriving the stiffnesss mass matrices for 2D frame element. But I'm looking for 3D frame element with...

Hello, There are two FoR S and S'. A and B in S FoR, A' and B' in S' FoR. A is a source of photons and B is a mirror. A' is a transparent glass and B' is a mirror. S' is moving to the right direction. Think that there is very negligible distance between A and A'. Now, A fires a photon beam...

the name says everything...but i want to know which metal is the besst to create infrared frequency and how far can it travel,bounce n come back with a detectable intensity? i know the 2nd question is stupid coz we r talking abt em wave they don't get absorbed in medium but they do get...

If I understand things correctly, the coherent state of a laser beam implies that the photon quantum field is a superposition of states with different particle numbers. This also implies that a laser beam is not in an energy eigenstate. To get energy conservation, I assume that this...

Problem: What is the equation that relates properties of a metal (modulus of elasticity, yield strength, elongation, etc) to how far it can deflect before permanently being bent. I can calculate how far a beam will deflect under different loading and support but I just don't know what the...

I’m having trouble getting my head around this example and solution that was given as part of a revision pack for an upcoming exam. Any explanation would be gratefully received. Question: A simply supported regular I beam is 90mm wide and 120mm high. The top and bottom flanges are 10mm...

I have a problem how to select the boundary condition when i answer this deflection of beam. for example: the boundary condition is [x=o,y=0],[x=l,y=0],[x=o,dy/dx=o] and [x=L,dy/dx=0] given that EIdy/dx= Ax+wx^2/2 EIy= Ax^2/2+wx^3/6 anybody can tell me how to select this?

Homework Statement http://i.imgur.com/5plXa.png Homework Equations ƩFx = 0, ƩFy = 0, ƩM = 0 The Attempt at a Solution I realize that this is an equilibrium problem and that the sum of the forces in the x and y directions is 0, and the sum of the moments is 0. I draw two free body diagrams, one...

λHomework Statement A symmetric confocal resonator with mirror spacing d =16 cm, mirror reflectances 0.995, and n = 1 is used in a laser operating at λ[o] = 1 μm. (a) Find the radii of curvature of the mirrors. (b) Find the waist of the (0,0) (Gaussian) mode. (c) Sketch the intensity...

Supposed in builiding contruction, the beam span is 12 meters compared to 6 meters. Would it make the beam size (and column size) twice in the longer 12 meters span given the same loading? Is there a law of physics that says the sizes are proportional to the span? Or is it algorithmic or...

Homework Statement Given a W21x68 beam with 1.388 kips per foot loading spanning 34 feet. The beam will carry the load but the maximum deflection is greater than wanted. We would like to put a W33x118 beam perpendicular to the centerline of the W21x68 (17 feet), to limit the deflection...

Hi there, electrician in need of some mechanical study help. The question I have is, A beam has a solid cross sectional area of 100mm and is simply supported by 2 supports 3m apart. Calculate the dead load that can be safely supported when applied to the middle of the beam. The only...

Question 1: On a typical wooden hanging sign you have three pieces of beam. One main beam extends upwards from the ground and at the top a beam slices through this (so that on one side of the slicing beam there is more beam than the other) with the sign hanging down from the longer section...

I have gone through Beam Element analysis in several books on FEA. 80% of books have a particular Stiffness matrix, while a very small number of books have a matrix which is subtly different in sign. http://www.flickr.com/photos/66943862@N06/7195680680/in/photostream/lightbox Most books have...

Homework Statement I'm unable to calculate the stiffness of the spring. Once, i get the stiffness i'd like to calculate the load required for the defined deflection. Homework Equations - The Attempt at a Solution -

In regards to the attached image; If the input photons were, for input b = photon #2, and for input c = photon #3, where: photon #1 and #2, and #3 and #4 are entangled as |H>|V> + |V>|H>, for the outputs:|H>(b’)|H>(b’) - |V>(b’)|V>(b’) + |H>(c’)|H>(c’) - |V>(c’)|V>(c’) + H(b’)|V>(c’) -...

Hi, I am trying to measure the center deflection of a simply supported beam with a capacitive sensor. The beam's surface that is the sensor's target is originally flat. After applying equal forces on the two edges of the beam, its center curves upwards (away from the capacitive sensor) thus...

Homework Statement I would like to know how to find the horizontal and vertical deflection of point C shown in the attached diagram. I also need to find the angle of deflection for point C. Homework Equations The Attempt at a Solution I've already found a solution to this problem...

Homework Statement A beam of light traveling in air hits a glass surface with refractive index 1.5 at 45 degree angle. The light is polarised at 45 degrees with respect to the plane of incidence. Calculate the polarization of the reflected beam. Homework Equations Boundary Conditions...

Hey guys, I know this is a simple question but I'm not really sure how to do it. Let's say we have a beam supported by two pins at both extremes. There is a central load on the beam, so it will deflect in the direction of the load. But we also have an axial force compressing the beam. My...

Homework Statement Homework Equations σ=P/A σ=My/I τ=VQ/ItThe Attempt at a Solution I'm on part C, pretty sure I have A and B, so I'm using a W18x46 Beam. I have drawn shear and moment diagrams. I just want to be clear on what part C is asking... I'm assuming this point is at the end of...

What happens when we send in a vacuum pulsed electron beam with a frequency 1e9Hz and power 1e6MeV? Thanks.

Homework Statement i had a solid rectangular beam of max stress equalling 1.65x10^6N/m² a new beam, a hollow rectangular beam is made to reduce weight, it has the same maximum bending stress 1.65x10^6N/m² but this time has a horizontal dimension of 0.2m and a constant wall thickness of 0.02...

Homework Statement Evaluate the ratio of the power contained within a circle of radius W(z) in the transverse plane to the total power in the Hermite-Gaussian beams of order (1,0) Homework Equations P=\intIdA The Attempt at a Solution I have determined the ratio for the Gaussian...

Hi, I haven't done beam deflection before. My textbook shows the usual simple beams with a perpendicular force acting on it. This one is a lot more complicated. I'm pretty sure the forces acting in the horizontal direction have to be added into this some how. Can someone look at the...

Homework Statement A uniform beam of length L and mass m shown in the figure below is inclined at an angle of θ to the horizontal. Its upper end is connected to a wall by a rope, and its lower end rests on a rough horizontal surface. The coefficient of static friction between the beam and...

Hello all. I am in the process of designing a mechanism for collimating laser diodes for a personal project. I don't have training in optics so I am stuck with this problem: I need to determine the focal length of a lens that can be used to collimate a laser beam with divergence 45 degrees...

Some have said it was 6000 degrees K. I'm not so sure. I know for sure that you can increase solar intensity arbitrarily by using lenses and mirrors. What I don't get is why this doesn't increase temperature beyond a certain point. Is it somehow related to the photoelectric effect? I guess...

Can anyone help me to find the answer,,, its a very difficult question! Q- calculate the safe inclusive UDL for a 356x171 UB67 simply supported at the ends of span of 9m. The permissible bending stress is 167N/mm*2 and the defluction must not exceed (1/360) x span, and I = 187.2x10*6mm*4...

Homework Statement A thick-walled wine goblet sitting on a table can be considered to be a hollow glass sphere with an outer radius of 4.00 cm and an inner radius of 3.40 cm. The index of refraction of the goblet glass is 1.50. A) A beam of parallel light rays enters the side of the empty...

In regards to this image - http://img.photobucket.com/albums/v608/steviet/image2.jpg: (a) when K is 45 degrees, when K reflects and E1 reflects, or K transmits and E1 transmits - the state of K gets teleported to E2. Photons E1 and E2 are entangled as |HV>-|VH>. Therefore if E2 is 45, then...

Homework Statement The rotation matrix below describes a beam element which is rotated around three axes x,y and z. Derive the rotation matrix. http://img194.imageshack.us/img194/3351/60039512.png http://img808.imageshack.us/img808/159/64794596.png Homework Equations -The Attempt at a...

I am a 3rd year civil engineering student and this is the first time i come across this problem and i am struggling with it. My problem here is that i don't know how to draw a shear force and bending moment diagram for a trapezoidal load on a beam with fixed supports at both ends. I know...

So for school I'm designing a ramp. The problem is that I need to calculate various things in it, none of which I've ever been taught, since I'm pretty sure it's all uni level. I've asked multiple teachers, including my physics teacher and my technology teacher, and they haven't been any help...

hi, not sure if I am posting in the right section, had a good look through the search option but cannot find what I am looking for, probably because I am being stupid.. im working on some simple beam calculations, I am a studying architecture, however I am trying to get my head round load...

Homework Statement Find the Fay this is static equilibrium so ƩF=0 and ƩM=0 Homework Equations ƩMa=0 = 2x5 + (-4x25) + (2Fby) Fby= 45 Newtons Using ƩFy we get Fay= impossible! Now if take the moment about point B i get ƩMb=0 = (4x5)+(-2x25)+2Fay Fay = 15kN Using ƩFy we get...

Homework Statement I have a bumper and I am trying to determine whether or not the rectangular tubing I am using to build it is strong enough to withstand a given load (rear end collision). The horizontal member is 4x3x.1875 tubing (4" base, 3" high, 95" long). Two 3x3x.1975 tubes are used as...

Homework Statement Calculate the force F1 to bend the beam AB to a radius of 7.5m. Assume the beam is a steel tube 200mm OD with wall thickness 20mm. The arm's AC and BD can be assumed rigid. The force F1 acts on pivots at C and D and is always in the x direction. Homework Equations...

Does anyone know of any good articles, journals or books that discuss the difference between simplified theoretical analysis of a beam under load and the actual real life effects? Need to do some reading up for an assignment but I'm having trouble finding anything of any merit! Cheers in...

So I just started learning to use the finite element package abaqus for modelling beam tip deflection under different loading conditions. I think I understand the theory behind it but was wondering if some one could answer a few questions about it to further my understanding. Firstly, how do...

I have never been able to grasp why certain mode shapes are the way they are. For example, I ran a free vibration analysis on a vertical beam fixed at the ground. The second mode shape is vertically straight. This is the same case whether or not I have a lumped mass at the top of the beam. Any...