Beam Definition and 1000 Threads

A beam of electron in vacuum with velocity v enter a region of spa e with a electric field E. The field is such the electrons circle with radius r. The electrons are now accelerating at constant tangential speed. Because this is not an atomic orbital then by classical physics the electrons...

Homework Statement I am trying to find the maximum deflection in a brass beam, however after taking a physical reading the theoretical answer I get is quite off and I am wondering what I am doing wrong. Homework Equations They tell us the max deflection is( Load*Length^3)/(48*E*Second Moment...

Why is it that equivalent length is so important for laser beam power output (Length = Power/60) - http://www.laserk.com/newsletters/whiteCO.html. I was reading that in order to get multiple kilowatts of power out of a CO2 laser beam you have to fold the beam a great number of times. Why is...

Homework Statement Homework Equations F=(del)p/(del)t The Attempt at a Solution I understand how to do part a, but on part b I don't understand why the change in momentum is 2pi. I originally did the problem by just subbing (del)p with h/lambda. Why is it 2pi?

Homework Statement If I consider a force, which is applied to both ends of a rectangular beam to its cross section with dimensions w (width) and h (height) and I know the length of the beam is l and the force is parallel, how can I calculate the stress? Also, what if the force were parallel to...

Homework Statement Calculate the reaction force at A? Homework Equations ΣMb = 0 The Attempt at a Solution As there is a pin joint at B it is possible to consider the bar only from A-B. From here I applied ΣMb = 0 120 + 20*2 + Ay*4 = 0 This gives Ay = -40kn Also since there are no forces in...

Hi, I calculated the scattered angle & the kinematic factors for both Al & Au to be Is what I did right? Also E (Alpha) = stopping power x depth = 250 x 0.5 = 125 keV As for the maximum & the minimum scattered energy i didn't know how?

Homework Statement Homework Equations W = -U for conservative forces F = qV x B = qvBsinθ W = Fd for conservative forces K = 1/2mv^2 sinθ = 1 for 90° angles E1 = E2 (conservation of mechanical energy) The Attempt at a Solution [/B] W = -U -Fd = U E1 = E2 K = U K = -Fd = -qvBsinθd K...

I'm looking for the max bending moment and max deflection of the beam shown in the problem statement. I tried using the double integration method to find the deflection, but it does not look right. I did the model in ANSYS to evaluate the solution, and the result does not match with my...

Homework Statement Hi! I have lately come across some tricky experimental physics tasks, where no solution is given. Some of them involved parts where the focal length of a convex lens had to be measured with a laser. How do you do this? Homework Equations 1/l + 1/d = 1/f (1) where f is the...

dear all , My question is what is the maximum load taken by beam of UB 610 x 229 x 125Kg/m for a span of 5 mtr? its supported on both side by anchoring on concrete beam.

Homework Statement Below are attached 2 beams, A and B. I have to calculate the vertical and horizontal reactions at both supports in both questions. I have done a lot of calculations and believe I have a good understanding of what is needed to be done however my forces are not balancing for...

Hi All, I'm trying to think through a problem and was hoping to ping the community for guidance. Suppose you have a beam that's symmetric about 2 axes (like a u channel or a triangular extrusion). Is it better to load the beam in compression on the side with material furthest away or should you...

Just a quick question. We know that an accelerated electron shoots out light, and light that falls on an electron in an atom, excites it. But what happens to an electron in vaccum, when it encounters a laser beam? If an electron beam from an electron microscope, were to to intercept a laser...

If I want to reduce the vibration of a beam fixed at one end, under a distributed load, does anyone know what this would involve? In the textbook, there is the idea of having a second system consisting of a mass-spring combination to reduce the vibration of the primary system. But I can't find...

In ultrasound what is the difference between beam steering angle and Doppler angle thanks

According to my optics book when you shine light on an object it exerts a pressure on the object in the direction of propagation. If light is made of alternating electric and magnetic fields, and these fields are in directions transverse to the direction of propagation, then why should the...

Hi all, I am interested in finding the power of a laser diode as function of the distance z, assuming a free space propagation. I think to have enough information to work it out but I am stacked at the moment. Given: the initial power, P0 = 1mW beam width clip (e-2 = 13.5%), wx = 3μm, wy =...

How do you get deflections of a fully restrained beam? :) I already solved for the propped reactions and end moments.. I'm not sure how to do that part. :/ ありがとうございます。 :)

There's this game called sword of the stars and one of the most interesting weapons is the meson beam. Essentially what happens is that mesons are generated and accelerated close to the speed of light so that they decay once they're inside an enemy ship, thus bypassing all defenses and creating...

Guys I have tricky question : I have beam loaded like that: Is there any easy way to do simplification of this load ( I don't mean transfer the UDL to Point Load). Mentioned that I mean the way to not do the calculation of moment to find max in 4 section and the two almost 4 double integrals...

Hi, I'm new here and I'm here to seek for help... I have this school project, I'm supposed to create an app (Funny that they asked an engineering student to do programming huh?). Basically this app involves beam calculations. It's supposed to suggest an appropriate beam sizing ( the cross...

if I have laser beam irradiated normally on the target surface and in the same time time it is p- polarized. under these conditions, we will have the electric field which is completely parallel to the target surface and have a great effect on the target surface. my questions is; is this...

Hi there, I'm solving the equation for the transverse vibrations of a Euler-Bernoulli beam fixed at both ends and subject to axial loading. It's a similar problem to that described by Rao on page 355 of his book "Vibration of Continuous Systems" (Google books link), except the example he uses...

Homework Statement Homework Equations ∑Fx=0 ∑Fy=0 ∑M=0 The Attempt at a Solution [/B] I am just concerned with part a. I got the correct answers doing this: First, FBD of segment AB: +cw ∑M_A=0: -136 - 6*By = 0 By = -22.7N two ways to get Ay: one: +cw ∑M_B=0: -136 + 6*Ay = 0 Ay =...

I am simulating a radio telescope and confused on what kind of source should I setup to simulate a star. Should it be a TEM00 gaussian beam or simply a plane wave?Cheers, Robin

I saw many of you saying in their posts that non-linear crystals like barium borate are the only means of producing entangled photons. And because they are expensive, only some of you can afford them. But I browsed the international science magazines and found this...

Homework Statement Doing some past papers but I got stuck to this question! Any medical physicists can give me a hand please? A patient is treated with a 6MVphoton beam, 12.5 x 12.5cm at 110cm (Source to Axis Distance: SAD) to a 9cm depth. The machine is calibrated to deliver 1.0cGy per MU at...

1. Homework Statement I have to calculate the tension of AB beam and the mass. The force of beam BC is 200N 2. Homework Equations My work The Attempt at a Solution T=226.10 M=25.01

Can someone explain why the slope dy/dx = 0 at x = L/2? L/2 is the midpoint and there would be a deflection here so surely the slope of the deflection curve shouldn't be 0? I'm finding it hard to visualise this. EDIT: I think I understand the above. The slope of the deflection curve at x = L/2...

I don't get how to solve this problem in the simplest form... I would appreciate your help thanks! I have had some attempts at the question but the question is supposed to be non-calculator-use, so the method should rather be simple, and I couldn't come up with any sort of neat way to solve the...

Hi, I'm struggling with finding the tensile stress at the mid-span of this beam. I've done the previous questions but have no idea how to begin with this one as I've never dealt with this question before. What is the general method? Correct answer is 1.66MPa. Thanks.

Homework Statement 1.0 mA proton beam accelerated through potential difference of 1 keV. Determine the volume charge density of the beam after acceleration assuming uniform current distribution within diameter of 5mm, with zero current outside of this. Particle starting from rest. Final answer...

Having trouble figuring out how to link the two Young's Moduli to the Bending Moment, any suggestions?

I am trying to understand in non-mathematical terms the meaning and physical reality posed by Einstein’s law which tells us that the speed of light is the same relative to all observers. I start with a basic hypothetical: Observer A observes B riding a motorcycle that is traveling at 50 mph...

Hello Everyone. I recently studied the Einstein special theory of relativity. I studied the thought experiment where a beam of light is thrown from a moving spaceship in the direction of its motion and the distance after a certain time interval was different from perspective of a man on...

A Gaussian beam has an intensity I(r,z), if the beam area at position Z is given by A(Z), then the beam gets focused by a lens of focal length f, what will the area of the beam be at the beam waist A(0) be? So I have been trying to figure this out for ages, I had to replicate an experiment in...

Homework Statement In the experiment of Davisson and Germer (a) show that the second- and third-orderdiffracted beams cannot occur and (b) find the angle at which the first-order diffracted beamwould occur if the accelerating potential were changed from 54 to 60 V. (c) What...

Hi, normally when we try to analyse a structural beam with composite section, we apply transformed section method or so. But what if two beams are just put together (one onto another one) instead of having a composite relation (e.g. glued together), how am I going to analyse the forces and...

What is the intensity in W/m² of a laser beam used to burn away cancerous tissue that, when 94.0% absorbed, puts 539 J of energy into a circular spot 2.11 mm in diameter in 4.00 s?? I've tried a couple different equations and I keep getting the answer wrong. This is due tonight, I'm super...

I am trying to make a FBD for equipment which is half out of the beam, I realize I can represent it with a single line of force. But how if I want to go for distribute load? which one is the correct one. (purposely not drawing reaction force on floor.)...

I think I am in a misconception concerning laser beams: Even the best lasers have a small line width. The spectral line is gauss-shaped. therefore the wave in position-pace is also a gauss-shaped wave packet, that travels with a certain group velocity. But this gauss shaped wave packet has a...

Homework Statement A beam of wavelength 600 nm has initially an intensity profile of Gaussian shape with a fwhm of 1 mm. Determine the intensity profile and fwhm 10 meter away.Homework Equations FWHM = λ/(2NA√(1 + I/Is)) The Attempt at a Solution [/B] FWHM1 = 1mm = 600 nm/(2NA√(1 + I/Is))...

regarding this equation, δ=(PL^3 )/(48EI) For the calculation of maximum deflection, if my structure is not longer a full form beam (meaning the structure has 6 holes drilled to it), can this formula still be used?is...

Bonjouro! Firstly, as this is my first post here, I would like to say thank you to everyone who is a part of the site and Hello! I've used this forum a number of times, but this is the first time I've posted here as this user! If the flexural stiffness of a beam is 25 MNm^2, and the beam is...

Hey guys, I am developing an program for calculation of reactions in a "4 point support beam". The problem is that this structure is Statically indeterminate and hence requires some other method. Support on any level is appreciated, especially from Civil Engineers. I will keep on posting...

Hello, Can anyone help me find the boundary conditions of the below given beam please. Its a clamped-free beam but the overhanging sectiona and the mass makes it confusing. Actually I am puzzled about finding the initial conditions.

I tried to work backwards and verify the magnetic field required by the LHC beam pipes. A circumference of 27km implies a radius R=4300 m. The beam energy E is 7 TeV per proton beam. Considering approximation E approximately equal to pc to get momentum (ultra-relativistic case). Plugging into...

Homework Statement The mirror in the image below deflects a horizontal laser by angle θ. What is the angle φ if θ = 60°. Homework Equations θi=θr The Attempt at a Solution So I know that, if I draw a line normal to the mirror, that will make it so that the incident angle and the reflected...

Hello guys, I have a simple question about the max bending stress in a beam. We know that in a cantilever beam, the biggest moment occurs at the wall. This is also the location of the max stress with equation stress= M*y/I , However, in a simple supported beam, we have This time, the max...