Beam Definition and 1000 Threads

1. Homework Statement A person with mass m1 = 61 kg stands at the left end of a uniform beam with mass m2 = 104 kg and a length L = 2.7 m. Another person with mass m3 = 68 kg stands on the far right end of the beam and holds a medicine ball with mass m4 = 8 kg (assume that the medicine ball is...

If a neutrino beam passes through an optics lens in principle does the matter in the lens focus the neutrino beam granted it may be ridiculously small amount? If the lens were instead made of compressed matter of nuclear densities would the answer change much? Thanks for any help!

Hi there! I have a couple of questions for you guys about Spatial Light Modulators and laser beam profile aberrations. In the laboratory where I work we have a setup with which we can create a Bose-Einstein condensate and do all kinds of funky stuff with it. We have (as far as we know) the...

Homework Statement Write a Matlab function to plot the displacement of a cantilevered beam under a point load. Annotate the figure’s axes and title the figure. In addition to creating the plot, the function should report (in the figure’s title!) the maximum deflection and angle between the...

Homework Statement A cantilever beam (prismatic, rectangular cross section) is loaded at the tip by a force P and at half its length L by a moment M. a. Calculate the reaction force and moment. b. Draw the shear force and bending moment diagrams Homework Equations ∑F=0; ∑M=0 The...

Homework Statement Find the deflection at x=L/4 and x=L/2 for the beam Homework Equations See attached pic. The Attempt at a Solution So I have the solution derived in class. Only 0<x<L/2 is derived because since the load on the beam is at L/2, the equation is valid for the...

Homework Statement A beam of positively charged particles with radius ##R## (current ##I##) is shot from a region of potential ##-V## through a potential difference of ##+V## to a grounded plate. The beam passes through a slit on this plate then passes through another region of length ##L##...

I just started my Mechanisms and dynamics class today for engineering. We already got the first assignment that's due in a day or so. The assignment consists of only 3 questions but first one is totally confusing me and I don't know what to do about it. I emailed the instructor 10 hours ago and...

In an article I am reading gold wires a fabricated on top of a substrate using electron beam litography. How exactly does a procedure like this work? Electron beam litography uses a beam of electrons to pattern a substrate. What exactly does this pattern consist of and how can it be used to...

hello I need to know about return current formation at beam plasma system, in a simple way. how It is formed?

I realize that there are two factors that must affect the directivity of a laser. 1, The length of the cavity and number of reflections and 2. The aperture of the exit or the subsequent optics. This must be related somewhat to the respective directivities of Endfire and Broadside RF...

Homework Statement Homogeneous beam shaped in letter L is suspended on two ropes of the same length l. The beam is of negligible thickness and its longer arm is three times longer than the shorter arm. Its overall length is l as well as the length of one rope. Look at each situation in the...

Homework Statement Draw the shear and moment diagram for the beam Homework Equations ∑Fy=0 ∑M=0; ΔV=∫w(x)dx ΔM=∫V dx The Attempt at a Solution I am firstly finding the external forces as any statics problem(Ay=13.5kN upwards, By=13.5kN upwards).Then I found the equations of the...

Hi, I just have some questions regarding the use of beam displacers, the below picture pretty neatly summarises what they do: http://www.fiberoptics4sale.com/Merchant2/graphics/00000001/What-is-Optical-Circulator-and-its-Appli_F29F/image_8.png My question is, what happens when polarised...

Homogeneous beam shaped in letter L is suspended on two ropes of the same length l. The beam is of negligible thickness and its longer arm is three times longer than the shorter arm. Its overall length is l as well as the length of one rope. Look at each situation in the figures. How can I...

I am struggling to remember how to determine the allowable delta max for a beam. I am currently modeling the bending forces upon a piece of square tubing, and though developing delta max seems rather straight forward, I can not seem to remeber how to determine just how much deflection I am...

I am struggling to remember how to determine the allowable delta max for a beam. I am currently modeling the bending forces upon a piece of square tubing, and though developing delta max seems rather straight forward, I can not seem to remeber how to determine just how much deflection I am...

Lets say we have a beam which is simply supported at the two extreme ends(support conditions don't matter in my question). A concentrated transverse load is applied at the halfway point. Now let's say we take a section at x= L/3 where is L the length of the beam. Now we know that transverse...

Hello everybody. I am going to propose an experiment with a proton beam at CERN for a contest. http://home.web.cern.ch/students-educators/spotlight/2013/competition-beam-line-schools. Also...

Homework Statement I want to know the section modulus for a beam which has a UDL of 13.5 kn/m across 10 metres. Its simply supported at both ends. max allowable stress = 255 MPa Homework Equations Z= M / max allowable stress [cm^3] The Attempt at a Solution max bending...

I'm working on a problem but I've hit a road block.. Then the cross section of the piece is here: The first part of the problem is to determine Iy, Iz, and Iyz of the member.. I found the y value of the centroid to be 2.8587" and the z value of the centroid to be 1.0734" using the...

Homework Statement Hollow circular beam with outside diameter 350mm, and wall thickness of 60mm E=60 Gpa beam length 2m Force applied to beam at midpoint of beam (1m from each end) F=200KN Force applie from the Top down, Ra , and rb from bottom up Homework Equations...

I have posted a link there to this thread so the OP can view my work.

Homework Statement How could I calculate the piecewise formula for M(x)? Homework Equations The Attempt at a Solution From constructing a free body diagram it looks like up until the pin support, M(x) = -Fy*x (Fy being the force pointing upwards at the wall) but I am confused...

Homework Statement A thin, uniform, 3.8kg bar, 80cm long has two 2.5 kg balls glued on at either end. It is supported horizontally by a thin, horizontal, frictionless axle passing through its centers and perpendicular to the bar. Suddenly the right hand ball becomes detached and falls off, but...

Alright, I took a while setting this problem up for you guys, because I am absolutely stumped and have hit a brick wall and have nowhere else to turn for assistance. Please excuse the shoddy diagram. I made it from scratch to try to illustrate the problem better. Homework Statement Find the...

Homework Statement An element is taken from the wall end of the cantilever beam that is loaded as per the diagram. What are the stress components of the element, taken at x=0, y=h/2, z=0 Homework Equations σ=My/IThe Attempt at a Solution So from the shear moment diagram, the moment and shear...

Homework Statement I'm supposed to solve for the maximum moment assuming the beam bends about the y-axis (not the z axis as shown in the image. Same image for different questions). I don't understand how to find the moment of inertia in this case. The solution gives the moment of inertia for...

Homework Statement Two identical, uniform beams weighing 260 N each are connected at one end by a frictionless hinge. A light horizontal crossbar attached at the midpoints of the beams maintains an angle of 53.0 ∘ between the beams. The beams are suspended from the ceiling by vertical wires...

Hello all, I am confused on how to calculate the maximum bending stress in an I-beam. I found the maximum deflection in each beam where the load is placed at the center of the span. I also know all the cross-sectional dimensions of the I-beam. Is it now possible to calculate it? Thanks

Hi guys, why does the following mean B is unitary? if we have two rotations such that; b1 = B11a1 + B12a2 b2 = B21a1 + B22a2 and the following commutator results are; [b1, b1(dagger)] = |B11|^2 + |B12|^2 --> 1 [b2, b2(dagger)] = |B21|^2 + |B22|^2 --> 1 [b1, b2(dagger)] =...

For this problem, I think that something is wrong with my moment equation, I am not sue how to find the loading as a function of x for this triangle shape. Do I need to account for the sections 0 < x < L/2 and L/2 < x < L??

Hi, I want to write a very simple code to plot the beam emittance knowing x,y,z and vx,vy,vz of each particle. I have generated with a tracking code a very simple beam (cone distribution with 1° divergence) and I want to compare the emittance of this beam with the one calculated by a...

Homework Statement A. determine the deflection at point A in the X and Y direction. B. determine the maximum normal stress in the beam C. determine the maximum shear stress in the beam Homework Equations δ=(PL/EA) (possibly?) δt=αΔτL d2v/dx2 = M/EI dM/dx = V δab=δx*cosθ +...

Homework Statement In cross-section, the beam you are working on is a gantry girder.The maximum bending stress in the girder must not exceed 25MN/m2 and the modulus of elasticity can be assumed to be 210GN/m2. Determine a suitable size for the beam, selected from the standard sections tables...

I am always wondering, when we are analysing beam structure where many externally applied moments are added on, why we can sum up all the externally applied moments and write equilibrium equations according to that. Because these moments are actually along different axes. Is it because in...

Homework Statement 3. In the model of “Empty Universe” consider a galaxy X, which starts emitting light at time t = tH/1000 (14 My). If, at that time, the proper distance between “X” and our galaxy was 10 Mly at what time the first light from “X” is expected to arrive to our galaxy...

1. Homework Statement 2200kg beam is sitting on two rollers spaced 2m apart. rollers weigh 1200kg and have radius of .35m. the block is pulled to the right with 4000N. there is no slippage. find the acceleration of the system (answer given is one of the rollers). 2. Homework Equations I...

We work on optical simulation where we use not ideal beam expander. Not ideal means that for beam expander designed for single mode (M^2=1), the output beam has M^2 >1 (M^2 = M squared) In our system we want to use beam expander with multimode laser beam. The beam expander is not ideal (for...

Homework Statement I am trying to find the minimum energy for a proton beam to make pions that have 100Gev of momentum. The proton beam is hitting a fixed target. Homework Equations p + n -> n + n + ##π^{+}## The Attempt at a Solution In the centre of mass frame, there is zero...

Hi guys, I've come across this problem and I'm not sure on where to start? Any help would be greatly appreciated. :cool:

Homework Statement A person with mass m1 = 50 kg stands at the left end of a uniform beam with mass m2 = 95 kg and a length L = 2.4 m. Another person with mass m3 = 60 kg stands on the far right end of the beam and holds a medicine ball with mass m4 = 14 kg (assume that the medicine ball is at...

Please find the attached picture. It clearly explains the problem What is the method to find the size of the knee braced beam member? Do we have to to draw free body diagram for each point and then find out the force acting on the cross member-then see if that beam's cross section area can...

Homework Statement A man of mass mm = 95 kg decides to paint his house. To do this, he builds a platform using a uniform beam with a mass of mb = 100 kg and a length of L = 7 meters. The beam is supported by two sawhorses, as shown in the diagram above. a) If the man stands over the support...

Hi i am new to the forum and hopefully i can get some help. I am trying to design a small parabolic light reflector that can be used with an LED array as being the source of light. The diameter of the LED array is 18.75mm. I am trying to obtain equations that would relate the diameter and...

Hi all, I am trying to find the slope of a T-stub joint at the bolt in order to find the bending stress of the bolt. I have drawn 1/2 of the T-stub as a beam. The beam analysis requires (for physicality) that the slope at each side of the beam to be zero. There is an applied load, a bolt...

Homework Statement Well actually we were doing a beam experiment in class. It consisted of varying the position of a load and measuring the reactions to eventually analyse the relationship between the distance of load from 1 support with the 2 reactions. The reactions were provided by two...

I'm mostly concerned with whether or not I understand this problem intuitively in order to answer the final part of this problem. Homework Statement Discuss the implications of Liouville's theorem on the focusing of beams of charged particles by considering the following case. An electron...

Homework Statement A beam of parallel light rays from a laser is incident on a solid transparent sphere of index of refraction n1 (see figure). (a) If a point image is produced at the back of the sphere, what is the index of refraction of the sphere? (b)What index of refraction, if any, will...

Homework Statement How do I find an expression for the deflection at midspan for a cantilever beam loaded with a uniformly distributed load? Illustration of beam: http://goo.gl/3SxeVZ Homework Equations \delta = \frac{Qx^2}{24EI}(6L^2-4Lx+x^2) The Attempt at a Solution Attempt at...