Beam Definition and 1000 Threads

1.Hey guys! I will need to design a floor with slab, beams and columns. Brickwall should rest on top of beam as possible. How about low wall, does it needs to rest on top of beams as well? Thanks! 2. No equation 3. I've designed some, but without low wall, that's what made me curious...

Hey guys, So just completed a question on a sign post subject to wind loading of 2 kPa where you had to determine bending moments across x and z planes (picture below), to determine normal, shear, max stresses and then determine the factor of safety depending on the beam type you chose. That's...

Hi I want to calculate the necessary incident polarization of a light beam at a given angle of incidence (theta_i) that reflects off BK7 glass (n = 1.5168) and is linearly polarized (i.e., 45 degrees). I know how to do similar calculations for incident natural unpolarized light, but not in the...

Compute the force exerted on the palm of you hand by the beam from a 1.0W flashlight. (a) if your hand absorbs the light, and (b) if the light reflects from your hand. What would the mass of the particle that exerts that same force in each case would be if you hold it at Earth's surface? On...

I've drawn the free-body diagram of an airplane wing spar. I know the magnitude and location of all forces. What is the procedure to construct the bending moment diagram?

Homework Statement Working out deflections on a semi circular bar. Homework Equations 3WR^3π / 2EI Where E = 200GN/m^2 W = 9.81N R = 150mm I = 5.625 * 10^-3 (bar is 25mm * 3mm) The Attempt at a Solution (3)(9.81)(0.15)^3π / (2)(200*10^3)(5.625 * 10^-3) = 13868.56 I have data that says it...

how to solve the large deflection of the beam, i have tried using finite element method but unable to find it.

For this we need a thought experiment: imagine you're on a gedanken planet manning a gedanken laser cannon, and it's pointing straight up. The light doesn't curve round, or slow down as it ascends, or fall down. It goes straight up. Now let's keep you safe in a bubble of artistic licence, and...

Homework Statement A 7.20m long rigid beam with a mass of 105.9kg is supported at each end. A 64.8kg student stands 1.33m from support 1. How much upward force does each support exert on the beam? (Enter your answer for support 1 first, followed by your answer for support 2.) Incorrect. Tries...

Hi, I am trying to mathematically model the rotation of a rotary flexible beam. There are numerous papers which study this topic but all of them are considering the beam as a fixed-free one. My case is different. This is the beam I am trying to model. The motor axis is at the square portion...

1. Homework Statement Express the beam energy loss in the accelerator in terms of the change in the beam momentum. It is taken from one paper, where \begin{equation} \Delta T = \left( \frac{1+\gamma}{\gamma}\right) \frac{T_0 \Delta p}{p_0} \end{equation}expression is used for transition from...

To give a little idea for what I'm aiming for: I want to make a prop laser gun. It doesn't have to actually do anything, but I've decided it'd be awesome if it did. I could use a 2-5W blue laser diode like some people who make awesome contraptions with lasers show on YouTube, but I'd frankly...

Homework Statement Two beams of different cross sectional areas are fused together to create a single beam, as shown in the figure above. The following relationships apply: A1 = 2A2, L2 = 2L1, E1 = 3E2. A tensile force F is applied at the ends of the bar, as shown. What is the ratio of the...

Is it possible to create a cantilever beam with constant or increasing stiffness. I've been experimenting with several different shapes and profiles, and have not had any luck. I know that there are shapes with constant stress throughout, but I'm hoping to find a shape with constant or...

Do you guys know a low-cost low-threshold optical beam limiter, with cost somewhere ~$100. Or if you know certain method to fabricate such. I would be greatful if you could include links and/or references. I am still noob in photonics so I am only familiar with a beam limiter that blocks the...

Can electrons be "guided" or "carried" by a beam of light, something in the manner of how a ship can be guided by a current? So suppose we emit a uniform field of electrons. I don't know if field is the right word. I mean a bunch of electrons of more or less uniform distribution are being...

The problem is attached.

Hello I am trying to setup a problem to represent a pipeline crossing over another perpendicular pipeline on the seabed. I am trying to represent the problem as a simple beam and having some issues with the supports i am selecting and the boundary conditions. Attached is a picture representing...

Hi guys, Hopefully a fairly simple question. All beam formulas I've come across, whether in my own textbooks or Machinery's Handbook, have two sets of formulas for beams. One will be for "simply supported", where one end is pinned and the other end is a pin-roller. The other connection type is...

How would one go about making a particle beam cutter? I'm thinking like a powerful laser type cutter. Please no mechanical engineers, I want a purely physics point of view.

How would someone go about to make a phased particle energy beam? What are the physics behind it? Any research that anyone knows on the subject that I could take a look at? Thanks

Hey all, I want to calculate the stress and strain on a beam using MATLAB and I would also like to make a stress-strain curve as well. The problem is as follows: I have a hollow rectangular aluminum beam that is fixed at both ends. I have the material properties and the dimensions of the beam...

Homework Statement Homework Equations FBD and all forces and moments = 0 The Attempt at a Solution Sketched in the image. So, I don't know how to go on with my analysis of the load, since I can't determine the reaction forces. Can someone please help me? Thanks in advance!

Homework Statement I just don't understand how to set the problem for the free body diagram (point (a) and (b)). Can someone help me with this problem? Thank you in advance.

I posted a question about Rabi frequency here https://www.physicsforums.com/threads/what-is-rabi-frequency.331082/ some times ago. The replies there answer some of my questions but I am still looking for detail explanation on the relation between Rabi frequency and the power of the beam. I read...

Hello, I can't find the formula for bending moment calculation of continuous tapered beam. the cross section is I (H) form, where web is 179.5 cm flange is 67 cm, web thickness is 1.5 cm and flange thickness is 2.5 cm. And this beam changes its height to 89.7 cm all other dimensions is the...

Homework Statement A uniform meter stick of mass M is pivoted on a hinge at one end and held horizontal by a spring with spring constant k attached at the other end. If the stick oscillates up and down slightly, what is its frequency? [Hint: Write a torque equation about the hinge.] The length...

what is the formula for the cantilever beam having two different young's modulas and moment of inertia, when a point load is acting on the free end. i have been trying but unable to get the formula. if the formula i can validate my project work and complete it

Homework Statement Homework Equations ΣF=0 ΣM=0 The Attempt at a Solution I think i correctly identified two 2 force members at A and B. But would the system be a 3 force member? If it is i don't quite know how to solve for the missing angles. Is the problem asking for the sum of the...

Homework Statement I have a 100cm beam with the fulcrum at the 20cm point. At the 0cm point is 300g which puts the beam into balance. Homework Equations How can I find the total weight of the beam and the torque due to the weight of beam using the given information.The Attempt at a...

So for sake of example the LHC beam one pointing at the other to cause a collision, the one beam is 6.5 TeV per beam. How can I calculate the volts per meter or given size of pulse? I understand that the particles have kinetic energy in the form of the speed of their travel but theoretically...

Could a particle(proton, gold ion, electron) beam reach the surface of the moon, given current technology? Would the beam diffuse too much too scenter the regolith? Or would the beam have to be focused or continually refocused in order to achieve that? If so why can they do it with laser...

Homework Statement A block of mass M = 1 kg is placed between a vertical wall and the end of A beam mass m = 10 kg . If μ S = 0.6 A , determine the minimum value of the angle θ min θ for which the block remains in equilibrium and the coefficient of friction Static B μ S corresponding to prevent...

So i have this simple situation where i have an electron beam with a certain kinetic energy, and i have a metal plate connected to the ground, and the electrons hit the plate, now i want to know the voltage of the current in the wire to the ground. Now i know both kinetic energy of the electrons...

I want to create a visible pattern of light from 1-5 feet away. The pattern would have a bright dot in the middle (ala sniper sight) visible in bright light at 5 feet. The cheap toy pointers seem to work just fine. It would also have a filled circular pattern around the dot, 8" in diameter at 4'...

I've seen various different matrices used to represent beam splitters, and am wondering which is the "right" one. Alternatively, are there various kinds of beam splitters but everyone just ambiguously calls them the same thing? The matrices I've seen are the...

Hello everyone! I'm struggling with something here. I am rusty so have probably just misunderstood something simple mathematically. There are equations to create the Bending moment diagram for each different type of beam subject to a UDL; cantilever, simply supported, fully fixed ends etc...

Hello, i was looking for ways i can reduce the deflection in the cantilever beam whose one end is fixed and load is applied at the free end. Few i thought of was, 1- Reducing the length of the beam 2- Increasing the modulus of elasticity of the beam 3- ?? 4- ?? 5...... Appreciate your help...

Not quite sure how to ask this, but here goes: I think I understand how a photon impacting an atom can increase the energy level of an electron in the atom. When I read about "light pressure", I thought, is there a way for, say, a stream of photons to accelerate an atom by continually impacting...

Greetings PFers, Would it be possible to move microscopic particles of a wide range of composition (conductivity, density, etc...) using a directed beam technology? The idea is to have a fast 3D printing technology (practically no moving parts) that is capable of depositing of a wide array of...

Hi, I've been trying to solve a problem which i don't even know how to approach. I have a vertical hanging cylindrical beam (free to swing sideways but not around itself), the beam is subjected to an eccentric load, downwards, at the bottom of it. The load is parallel to the swinging plane (it...

Hey! I am trying to figure out this one problem. Some help would be appreciated. How can i relate the maximum distance traveled by an electron at a given pressure? So electron is colliding with air molecules. I wonder if there is a formula or derivation which relate maximum penetration and...

Homework Statement http://www.upload.ee/image/4762203/DSC_0009_1_.JPG I need to find the formula which is in the red circle. Beam is simply supported at both ends and there is center load. Do you think that this is correct? Homework EquationsThe Attempt at a Solution

No matter how many explanations of SR I try to read this honestly really bugs me :-) Perhaps someone here can provide a different perspective that will make it click for me, i don't know... The way I model the problem is thus: A C B there being 2 inertial frames, one for A&B...

Today, I discussed my friend about two rigid beams impact and assuming no energy loss in the impaction. As in the above figure, the upper beam move down with a uniform velocity ##v_c##, and hit a beam with ##0## velocity. After that the above beam will rotate and move away, which can be...

1. The problem, I have a beam 9000 mm in length. assuming a x-coordinate system: supports are at the x= 1500, x= 4500, and x= 7500 positions. there's a uniformly distributed load (let's call it w) through the length of the beam (from 0 to 9000mm) Solve for the MAXIMUM moment. This would be much...

Hello If a heavy ion beam deposits a certain energy E in a volume V, how many ion-pairs will it produce in matter? I think that the number of ion-pairs will be the energy divided by the (average) energy of ionization. A friend told me that a part of the deposited energy will cause also atomic...

Homework Statement Derive an equation for the deflection using Macaulay's method. Hello all, New member here, I come across this forum for advice regularly and have decided to register :). I have been given a problem that is highlighted in the attached picture. I am competent in calculating...

Hi, I´ve tried to calculate the vibration modes of beam in the space, without gravity or any other force. The forumle of the beam is this one: Cos(λL)*Cosh(λL)=1 from which I´ve calculate the roots and the resonance. I´ve found a programme for Matlab that calculates the vibrations modes if...

An observer outside the rocket sees a light beam through a rocket that's accelerating. How will an observer inside the rocket see the light beam? (The problem is showed in the picture below) My friends and I had this problem at school today, and we couldn't decide which is right. Here are our...