Beam Definition and 1000 Threads

I'm a "layman" when it comes to physics and I read in the FAQ that a photon is not a real particle but is described as one for the benefit of lay-people. I read that 65 billion neutrinos pass through a square centimeter every second so I wondered how many photons pass through a square...

For some of the high powered LED lights, the beam seems to have bright and dimmer sections along its length when projected through air. They seem to be regularly spaced rather than random. Some people have described it as looking as though the beam would get thinner and wider along its...

Hello, I would like to know how to find the deflection of simple 2 beam assemblies. In college, I remember only doing one beam problems. For example, a beam supported at both ends with a load in the center would follow the equation v_max= -(P*L^3)/(48*E*I). What if 2 identical beams...

Hi all Sorry if this is in the wrong place... I've been doing some beam deflections on a simply supported beam, with loads applied to the overhangs, and have used MDSolids, Hand Calculations and Solidworks. My hand calculations match up with the results that I have got from MDSolids...

Homework Statement In a certain particle accelerator, a current of 300μA is carried by a 4.00-MeV proton beam that has a radius of 1.30 mm. The mass of a proton is 1.67 x 10-27kg. If the beam hits a target, how many protons hit the target in 3s? Homework Equations The only equation that...

Homework Statement http://data.imagup.com/10/1146211599.jpg A,B,C and D are 4 beams ..what beam we can change it to chain and this system till stay work perfectly?

curious as to the proper way to model this. beam is symmetric so centroid is in the middle (used to calculate distance from centroid d in bending moment of inertia equation) bending moment of inertia is I =\sum(I + Ad2) I=\frac{1}{12}bh b=base h=height d=distance of the area's...

Hello guys, I've created beam3 using Nodes. How can I do Meshing? Or for Nodes it is not possible? I can not create the beam by keypoints, cause I need to do stepped beam with different cross-sectional area. Thank you.

Homework Statement - Compute the reactions at the supports - Draw complete shearing force and bending moment diagrams - Determine magnitude and location of maximum absolute value of shearing force and bending moment - Use free body diagram approach to determine internal shearing force and...

Moment Diagram for "Boomerang" shaped Beam Hey y'all, I'm trying to determine a moment diagram for this "boomerang" shape (a picture is attached). Its been a long while since I have done mechanics, and I can't remember the relevant equations or how to best approach this problem. I will be...

Say we have a laterally insulated beam and some boundary conditions at either end, be it convective or fixed-temperature, but the cross-sectional area is variable. If the cross-section were constant I'd just say it were a 1-D problem, but I'd imagine that having the cross-sectional area be a...

Homework Statement Calculate the reaction MA http://alkaspace.com/is.php?i=134123&img=E-3.1.jpg Homework Equations The Attempt at a Solution First I have put the reaction By as an hyper static force. Then I found the deflection in B with the force By as a variable. vb=...

I'm simulating an ion beam with different charge states passing through two pinholes. I'm using random angles, from an external function, to evaluate the velocity components along the axes and solving the differential equation: O=[0 0 0]'; f = @(t,ys) [ys(4:6); O]...

Im trying to generate a simple beam program in mathcad and am having trouble with the integrals. Attached is what I have so far:

I am trying to write shear and moment equations in mathcad for a simple beam problem. Any help would be greatly appreciated. Thanks

Homework Statement A beam of electrons is fired into a rectangular region of space that contains a uniform magnetic field in the -z direction. The electrons are moving in the +x direction, as shown. The speed of the electrons in the beam is 6.00 × 106 m/s. The mass of an electron is me =...

I'm writing a script to simulate the transport of ion beam in a Thomson Spectrometer. My concern is that the program doesn't allow the passage of higher charge states through out the pinholes that I use to collimate the beam. I mean if I want to simulate a 3 charge states beam of C ions I will...

Hi Guys, Please see attached diagram. I have done the maths but i am not convinced. Maybe i have missed something but i have not done structural maths for a while. I am using Force = ma where m= mass and a = 9.81m/s2 I need a deflection value for a mass of 19000kg And a mass for...

Homework Statement The crates( one create 500 kg) are placed on a hydraulic lifting beam: 1. State the order of lever used here 2. Calculate the effort required to lift the load 3. Calculate mechanical advantage for this system 4. Calculate the velocity ratio for this system. If the...

Homework Statement (Refraction) A parallel beam of width W is incident on a interface. The index of refractions are n1 on the incident side and n2 on the transmitted side. (a) Find an equation that gives the width of the transmitted beam. (Assume there is an exit beam. IE we are not...

Homework Statement A bridge is idealized as a simply supported beam AB of length L, as shown in Figure 2. A four-wheeled vehicle of weightW now drives across the bridge. Sketch the shear force diagram for the case illustrated, where the rear wheel is a distance a from the left support...

I was reading about Earnest Lawrence and a question dawned onto me; Let's say you bombarded a metal, let's say iron or copper, with high energy protons coming from a cyclotron. The protons going from the "dees" into an accelerating vacuum tube with the specimen at the end. Would the proton beam...

Homework Statement I've been set the task to come up with a solution/equation for a beam with a known mass (M) which is acted upon by a force (F) which is pivoted about a point. The other side of the beam is connected to the floor by a spring with a spring constant (k). What I'm trying to do...

hello, i am involved in a private project. for this project it is necessary to control a huge amount of loudspeakers (intensity, frequency) in order to achieve beam forming of the sound waves. However, since i am not an electrical engeneer i really do not have a clue how something like this...

Is the speed of light what they call the front velocity, the formost part of a beam of light? If this is so the actual path of the electromagnetic wave must travel further than the distant traveled by the beam of light. So any point along the path of the wave must be traveling faster than the...

Homework Statement Beam of electrons (charged particles!) is directed to copper absorber with known energy (E= 10MeV) and intensity (10^8(s*cm^2)^-1) . I need to find the thickness of absorber so that all electrons would be absorbed. Also under what conditions does it happen and what is...

Am i right in saying i can use this formulae: - W/EI((x^3/12) - (xL^2/16)) + w/EI((Lx^3/12) - (x^4/24) - (xL^3/24)) please help. See attached question. Question aii. Thanks

Homework Statement Several beams of 533 x 210 x 92 kg/m UB section in grade 5275 steel are used to support a composite floor slab. Each beam is simply supported with an effective span of L=6.50 m. (a) During construction, before the floor slab is cast, a temporary concentrated load P kN...

Homework Statement I have a piece of metal with one end fastened to a table by a clamp and the other end off the table. I only know the length of the beam and the strain. I am trying to figure out the stress in order to figure out youngs module so the metal can be identified. How do I do...

Homework Statement A timber beam will be used to support part of the ceiling of a house. It is going to be attached to the walls as a simply supported beam, Figure 6. If three forces are applied to it and considering the weight of the beam as a uniformly distributed load of...

hi everyone, I have a question concerning the magnets physics more precisely about the Kickers/Dipoles. For my work, I need to design an optical system capable of deflecting a proton beam (4 GeV) switching between to 2 angles (+ 118 mard and -118 mrad) in a raw. Can a pulsed magnet...

Hi there, I apologise that I should probably know this/its a stupid question but I seem to have forgotten all physics over the holiday and so any help would be great! I have been told that there is a beam of atoms with spin quantum number 1/2 and zero orbital angular momentum, with spin +1/2...

Homework Statement http://img408.imageshack.us/img408/3397/21695637.png q=0.4905 [Nm] q2=20 [Nm] Homework Equations How to find the moments? The Attempt at a Solution I looked of a few books in last several hours, but without any success. In every similar problem the moments are...

1. The refractive index of the Earth’s atmosphere is n = 1.01 + α(R − r), where α is a constant, r is the radial distance from the Earth’s centre and R = 6.4 × 10^6 m is the Earth’s radius. By considering a path comprising a series of total internal reflections or otherwise, find a value of α...

Homework Statement I'm trying to work out the moment of inertia for this L shaped beam: http://dl.dropbox.com/u/630750/Screen%20Shot%202011-12-31%20at%2017.54.34.png Homework Equations (Included on my sheets below( The Attempt at a Solution I've made two attempts, the first...

Homework Statement A symmetric I section beam is 60 mm deep with a second moment of area of 663x10-9 m^4 and a cross sectional area of 1600 mm^2. It is subject to a bending moment of 1.2 kN.m and an axial force of 25 kN (tension). Find the maximum tensile and compressive stresses.Homework...

I have been trying to solve this question using the superposition method, but cannot seem to get the correct answer. Can anyone help? Question & formulae are attached. Cheers, G

Hey everyone, I'm having some trouble with my material science homework. I really have no idea where to begin: Consider a piece of beam of 1 cm in length with one end fixed on a wall and the other end free (see illustration below). If you bend the beam by applying a force at the free end...

Homework Statement 01"{ 5. (12)A balance beam device comprised of a 200 cm long beam of unobtainium (no mass) ] \]and a fulcrum located in the middle of the beam is balanced straight and level. At the right side of the beam system a mass of 30 kg is attached and at the other end of the...

Homework Statement I have attached the problem. I am confused about how they got x(θ) and h(θ). From the diagram it looks like they made it with reference to the triangular support beam. Why? Homework Equations The Attempt at a Solution

Illustration attached --> https://www.physicsforums.com/attachments/42037 I have a question which requires me to calculate the maximum stress in a simple supported beam. The beam is 3 m long and rectangular and has two forces acting down vertically totalling 20 kN. The breadth of the cross...

I saw in some building constructions where they pour concrete in half of the horizonal beam (with rebar skeleton). Then the next day, they pour the other half of the rebar skeleton. This means the center of the concrete is not contniuous and only the rebars in the mid position holds the...

Homework Statement A 120 kg beam is 12.0 m long and has 2 supports, each of which are placed 2.0 m from each end (leaving 8.0 m of the beam between the 2 supports). A 50 kg student stands at the extreme left end of the beam, 2.0 m left of the left support. A second student stands 1.0 m from...

Hi! I'm looking for information on how one would size a wide-flange beam knowing the live/dead loads and the span required i can't seem to find any calculations for this sort of thing! beam is not composite with floor

Hi, Calculate the dimensions of a solid rectangular beam using the information below: Max Bending Moment= 8280Nm Ze = 36cm^3 Allowable Stress = 230MPa d = 2b Stress = moment/section modulus

Homework Statement Question: Sketch the cross section of the gantry girder and indicate on it the position of the maximum bending stress. State if this stress is tensile or compressive for this particular example, explain how you decided Homework Equations There aren't any required...

Homework Statement See problem number 2 as attached. The Attempt at a Solution I found the reactions and shear and moment diagrams for the original beam. I also drew the conjugate beam and loaded it with M/EI. My only question for this problem is what the 4EI and EI under the beam...

Homework Statement A 26.6 kg beam is attached to a wall with a hinge and its far end is supported by a cable. The angle between the beam and the cable is 90°. If the beam is inclined at an angle of theta=13.3° with respect to horizontal, what is the horizontal component of the force exerted...

Homework Statement Hey everyone I'm new here and I'm completely stuck on the logic behind this question. A 230 kg beam 2.7m in length slides broadside down the ice with a speed of 18 m/s. A 65 kg man at rest grabs one end as it goes past and hangs on as both he and the beam go spinning down...

Homework Statement Construct the slope and deflection diagrams. I've attached the problem with the original diagram (problem #1). The Attempt at a Solution Considering the number of diagrams required, I thought it would be best to attach a photo of my work. I drew the shear and moment...