Beam Definition and 1000 Threads

Hi guys, I don't really know how to cope with this problem, maybe just because I can't properly understand the data. In the figure we have a beam with its loading(plus a force of 15kN), a pivot O and support at the rightmost point. I would say that in order to find the equivalent system, I...

First of all I want to ask , do the LHC power klystrons work always in CW or are their frequency shifted to correct for timing of the bunches in the LHC tubes in case something isn't aligned or doesn't that ever happen? Also how do they drive the klystrons at LHC or other CW operation from an...

Can someone please tell me why I get two different result of the value of Cy (please see attached image for more detail)? Am I doing a mistake? If yes, what is my mistake?

Hello everyone, I hope you can give me hand with what I will present. I have a beam with cross-section shown below. I considered a simple linear hardening model for predicting the stress and strain developed by bending the beam on the radius ##R_0## around the y-axis, where: The strain...

Generally, one would expect the beam to lose its content (energy or particles) if it hits anything before its reaching its target. The whole idea of maintaining (conventional) vacuum using pumps or other means is to minimize that loss. But is it possible that there could be a beam loss purely...

I have a beam splitter operator (a†)b +(b†)a. Does it commute with exp(αâ†-α*â). Here a and ↠are creation and lowering operator

v_g+v_e=15/t_1 v_g-v_e=10/t_2 v_g=s/(t_1-t_2) But there are too many unknowns. What am I missing?

Summary:: I did the first section but I am having a hard time with the second. would like to find the moment in the next section (from b to h)

There are optical crystals that can convert a small fraction of the incoming beam of light into light of different frequency. See the Wiki article, https://en.wikipedia.org/wiki/Spontaneous_parametric_down-conversion "Spontaneous parametric down-conversion (also known as SPDC, parametric...

Pretty much the title. Just some brain teasers I'm trying to figure out. I can't think of how a cross section would come into play when it comes to axial loading. Buckling? Since the critical force for buckling is proportional to moment of inertia, so theoretically if I have a high moment of...

I have a weight of 30,000 lbs distributed across a span of 100' and supported at the ends. If I have 3 beams to support this load, each beam would then need to hold 10,000 lbs, and with a F.S of 1.6 each beam would need to hold 16,000 lbs. If I assume my max deflection at 1", then I can find the...

I know the answer is 170 but I am not sure how to get there. I tried doing things backwards g=9.8 t = fr = mgr 0= 170 + tbl - tbr - 5x9.8x1.5 0= 170 + tbl - tbr - 73.5 -96.5 = tbl - tbr -96.5 = 18*9.8 * 0.2 - 18*9.8*1.4 -96.5 does not equal -211.68

Electrostatic repulsion of two electrons is about 4.17*10^42 stronger than their gravitational attraction, and is mediated by massless carriers. Black holes preserve charge, and charging a BH with even a moderate electric (negative) charge will result in BH repulsing electrons instead of...

I am only asking about part e. If you are short on time, you can read through parts a - d, to get an idea of what is happening, and then attempt part e directly. I have solved parts a - d. If you would like to check your answers, the answer to part c is [rne^2 / 2e0] [ 1 - (v/c)^2], and the...

This is the analytical working out. I substituted the value of 306mm ( the maximum length of the beam) to find the maximum deflection along the Z-axis. Which came out to be -2.39mm. But according to Ansys the average deflection is 0.3mm and the maximum deflection is 0.8mm. This is the Ansys Values.

Say that I have a continouos beam resting on top of column spanning across 3 column. The applied load is UDL on the beam, here's how the BMD look like. My question is whether the connection between the beam and column need to sustain the moment ? Which point need to sustain the moment ? All 3...

The only knowledge I have about such reflection questions is theta=2theta. But I missed class when this was thought. Please I need help and guide

I keep seeing that it's assumed that photons interfere with each other, and there are other points of proof for this like destructive interference, etc., but I've never seen an experiment in which a constant beam is used but both slits are analyzed or the energy required for measurement is...

If we do not consider diffraction,why lasers rays are parallel?Do atoms stimulatedly emission photons in same direction?It seems to me stimulated emission photons have same frequancy but random in direction?

Finding the neutrons per second. Uncluttering the question: ##P = 6 \times 10^{7} J/s, E_{1} = 149.7 MeV/event, A = 10^{-4} m^{2}, R = 5 m ##. Number of events per second = ##\frac{P}{E_{1}}## = escaping neutrons per second Area of ##5m## sphere around reactor = ## 4 \pi R^{2} ## Fraction of...

Hello, I'm looking to construct a simple rectangular 13'x17' hollow steel frame over my patio, but I'm getting conflicting beam deflection calculations. I need to determine my beam size for my long spans of 17'. My plan was to use 3.5"OD A500 structural steel. 11 gauge (.120 in) wall...

Hi all, I have calculated that a wooden rectangular beam has a max bending moment of 1780N/m2 and I want to increase loading by 10times and use the table for a replacement steel i-beam. Steel max stress = 275MN/m^2 and safety factor of 2 How would a suitable beam be confirmed given the data...

Can you help me answer this question please?

I have been researching all night and can't find much useful relevant information on this subject. I have gone back to the physics roots and played with ray diagrams and specific heat calculations but all of these theoretical possibilities have tons of real world variables and that's where I'd...

When one of the pivot is pulled, just at that moment a couple is formed due to the normal reaction from the existing pivot and the weight of the bar. From the assumptions given in the question, we can state that the distance between the two forces (N & W) giving rise to the couple is L/2. Using...

I am wondering if one of the prerequisites of the double-slit experiment, when done with electrons, is that the beams must be in a dark vacuum tube so as to not destroy the interference pattern. I am trying to learn if the beams will lose their interference pattern because the particles of the...

Could I please ask for help with the last part of the following question? I have the first two parts done, answers are: Distance of COG from A = a(1+n)/n and W1 = W(1+n)/3 I can't see how to go about the last part. Here's my diagram for the system prior to the torque L being added: In...

Please help to check whether I did it correct, thanks

Stable nuclei have radii that are approximately given by the formula: R = r0_A^1/3 Where r0 = 1.25 × 10−15m and A is the atomic mass number. In many experiments of interest to modern particle physics, beams of neutrinos scatter from nucleons within the nucleus. Even though the nucleus is at...

I am reading a journal article from Balduzzi about shear stress recover on tapered beams. I can not get the exact constants he gets and I am stumped. Above is solving for differential piece of the beam. Equations 16-18 are the ones I am trying to calculate. I attached my work and the...

This could also be posted in the Math / differential equations sub, but it also involves the derivation which is classical physics. So I was doubting :smile:. So, I'm dusting off my dynamics a bit and found this problem of a thin beam on a frictionless surface in a different forum and decided...

I was reading about electron-positron annihilation. Typically it results in two photons, each with an energy of 511 keV, that go shooting out in opposite directions. But I read that in some instances three photons can result. Electrons have an intrinsic spin of ½, while photons have a spin of 1...

Hi, some time ago I wondered if it's possible to calculate fatigue life (number of cycles to failure) for complex models analytically, based on static FEA results: https://www.physicsforums.com/threads/fatigue-life-hand-calculations-based-on-static-fea-results.994264/ Unfortunately, it seems...

Before to open this topic, I found this there. It's quite similar, if not the same, but I'm a little confused, so I'm here. The situation is represented in this image. From optical geometry, ##\theta_{incident} = \theta_{reflected}## The four-momentum in ##S'## is the following one...

Hi, Is there anybody who knows about this subject and can guide kindly? Regards, In electron beam lithography, there is an optimum aperture angle to obtain a minimum beam size: a) Determine this angle considering only the influence of the source and spherical aberrations. b) What is the...

Since the "non-uniform" hypothesis I got confused about how to solve this problem... in which way could I find its center of mass, if its mass is not distributed uniformly? Another question I have with regards to this static situation is: is the beam placed horizontally? If not, how could I know...

Dear Everyone： Q： Please help me to understand why the torque of external load to the centroid is different from the torque of internal shear flow to the centroid in the asymmetric beam? Attached please refer to the following link for more details. Question version Original version Thank you...

I assumed that the vertical force at point B would be the same as the force between beam CB and E because of Newtons law. Did I assume wrong? Look below for my calculations and answer which I got to 250N. I don’t know the correct answer but assume someone here can tell me if I solved the problem...

Hi, in the book titled "Formulas for Dynamics, Acoustics and Vibrations" by R.D. Blevins, I've found a formula that can be used to calculate the bending stress in a cantilever beam subjected to harmonic force applied at the free end. The formula looks like this: $$\sigma=\frac{F_{0}Ec}{m...

Did anyone ever create a beam of anti-hydrogen to see if antimatter reverses the direction of time?

there is anything that have input of two laser and output one laser with a bit bigger radios or just stronger laser like a beam just the opposite instead of splitting one sources connect two sources

Hi, I am trying to figure out how many 1" steel square tubing pieces it would take to support a 500lb weight extended out 40" on a cantilever. I have seen Modulus of Elasticity figures ranging from .029 GPa to 200 Gpa for Steel. The steel I plan to use would be common hot rolled square tubing...

This seems like it should be an easy and obvious thing to look up, but I had the hardest time finding it. Is there any graph which shows, as I increase the beam energy of a particle accelerator, what particles can be produced at each energy? Just looking for something ballpark here. Obviously...

Let's say I have three modes in a fiber that is elliptical cylinder shaped (cylinder with elliptical facet), as in the image below (the source:Optical Engineering, 46(4), 045003 (2007)) so what is the equations that describe these fields..

Is there a limit on the minimum diameter that a collimated electromagnetic beam must have (lasers or masers), in terms of its wavelength, or it is possible to create a beam with its diameter smaller than its wavelength? I'm considering a colimated planar wave directly from the source, and not...

This is my sketch: I think the only possible way to get emergent beam perpendicular to AB is when the incoming ray is refracted towards side AC then total internal reflection occurs as shown in my sketch. Angle QAR = 60o and angle ARQ = 90o so angle AQR = 30o It means angle CQP is also 30o...

Hello, I've a particle beam moving along the z-axis. The beam goes through a dipole magnet. I studied the hit position in a tracker after the magnet and I noticed that there are hits at 2 different x coordinate (the x asix is transverse to the z one). Let's call Delta x the shift between the 2...