Beam Definition and 1000 Threads

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...

I'm trying to find a solution to a system in which a clamped free Euler-Bernoulli Beam system rests on top of a mass-spring-damper system. The MSD system has nonlinearities in both the spring and the damper and is of the form: I have extended the nonlinear restoring force to its 3rd term and...

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...

I am calculating the all reaction forces in this beam. However, I want to ask: By taking moment about point B, why does the moment of the UDL become 15*7*5.5 instead of 15*7*4.5 Thanks !

Hi all, Having trouble with the following question, trying to work out the FBD and forces. I am fine with working out the max tensile and compressive forces however I can't get that far as the two hinges are throwing me off. As I understand, the moment at the hinges should be 0, is this...

I pass a river with two bridges on it, right next to each other. One older, one newer. The newer one is all concrete construction & the shape of its spans makes intuitive sense to me i.e. minimum thickness at mid span. Like this sketch: The older one has sort of the opposite shape with max...

Homework Statement Calculate the minimum beam energy in a proton-proton collider to initiate the p+p→p+p+n0 reaction. The rest energy of the no is 547.3MeV.Homework Equations For a head on collision between particles a and b, from conservation of total energy: Ex = Ep + Ep' = 2Ep so that...

Homework Statement The uniform I-beam has a mass of 74 kg per meter of length and is supported by the rope over the fixed 300-mm drum. If the coefficient of friction between the rope and drum is 0.50, calculate the least value of the force P which will cause the beam to tip from its horizontal...

Hey everyone, I was just wondering if someone could explain to me what Bending stress is? Supposed you have a cantilever beam with a point load at the free end, I know that the bending stress will decrease as you move away from the fixed end? but why? and how can you back that up? Also, as...

Hi all, my professor has hinted at proposing a question of this sort to us for a shear and bending moment diagram. Now while I am comfortable with having [either] a uniformly distributed load or a varying one, I'm not sure how to deal with both. I can't seem to find anything in my textbook to...

Hey, all, So I posted a similar thread yesterday about my project design issue, but I've made progress on it by taking a different approach. For the project, I have a cantilever shaft of fixed length (1.2m) and a tensile axial loading, and two torsional loadings in the same direction at...

Hi, I have a Fourier problem that i do not know if it is valid to do the calculations like this. The Fourier transform looks like this ## \hat{v}(x,\omega) = \frac{\hat{F}(\omega)}{4(EI)^{\frac{1}{4}}i \omega^{\frac{3}{2}}(\rho A)^{\frac{3}{4}}}\left[ e^{-i\left[\omega^2 \frac{\rho A}{EI}...

Homework Statement In plane parallel plate the refractive index is a function of coordinate ##z##, so that ##n=n_0 -{n}'z^2## for ##{n}'>0##. The origin of the coordinate system is in the middle of the layer, and ##z## is parallel to the normal of the layer. In paraxial approximation calculate...

Homework Statement Two 8.0N forces act at each end of a beam of length 0.60m. The forces are parallel and act in opposite directions. The angle between the forces and the beam are 60 degrees. What is the torque of the couple exerted on the beam? 1. 2.4Nm 2. 4.2Nm 3. 4.8Nm 4. 9.6Nm Homework...

1. A transversely directed transient force F(t) acts at the free end of a semi-infinite beam. a) Show how displacement, velocity, acceleration and strain at an arbitrary position along the beam can be determined. b) Calculate (MATLAB) the transversal acceleration (or an other quantity) at an...

I am a Post graduation student and I am doing a project on the conversion of a Gaussian beam into a flat top beam using optical components. I have found that the best component to do the same is a Powell lens. I would like to know more about the equations connecting the input beam diameter...

Hey all, So I have this beam problem and I honestly am lost with it! The beam is I-section cantilever, tapers in depth along its length (See picture attached) with a point load at the free end. I am trying to figure out the deflection formula and how to derive it! Also, when calculating its...

Consider a beam with an upwards concentrated force applied to its center. This is equilibrated by a distributed downwards force. There are no displacement boundary conditions. I've tried approaching this with simple beam theory, but I can't get a complete answer (shear, moment, slope...

Homework Statement Using continuous beam theory, constructing BM diagram from points b to c, to calculate the max deflection. I only found a have a single solution, though the BM digram show two points of zero bending. I can provide the solution. [edit: Rb = 685 N] Homework Equations...

Hey all, So I've been writing a hard science fiction novel and need real answers from someone who understands the fields better than I ( I have no formal education outside basic high school classes in physics) The problem I have is I'm not a fan of faster than light travel but I need a way for...

Homework Statement Calculate the normalization parameter A in the wavefunction ## \varPsi(x,t) = A e^{i(k\chi - \omega t)} ## for a beam of free protons traveling in the +x direction with kinetic energy 5 keV and a density of ##7.5 * 10^9 ## particles per meter beam length. Homework...

When you accelerate higgs.. would it travel the same as photon with alternating magnetic and electric field traveling on permissitity and permeability of the vacuum. In other words, how do you make scalar particles travel? If we can make really sensitive Higgs detector.. then you make higgs...

I have A beam of 1.2 m long, supports at 0m and 0.8 m. forces of 10 N at 0.4 m and 5N at 1.2 m I need to find the deflection equation for this situation. Can someone have a look and see if they can come up with the equation. As I have tried but my results do not match what I am expecting

Homework Statement We were shown this image ^ We were later told that it is suggested that the depression (y), is directly proportional to the length of the beam cubed (L3). We were asked to give reasons why this is so. EDIT: The 1kg mass is placed at L/2 Homework Equations y is directly...

Homework Statement An optical fiber is one way to guide light efficiently from one point to an other. It is currently used for data communication: it offers low loss and very high bandwidth, ideal for the requirements of the internet. Generally, we can describe an optical fiber as a medium with...

Homework Statement For the simply supported steel beam [E = 200 GPa; I = 129 × 10^6 mm4], use the double-integration method to determine the deflection vB at B. Assume L = 4 m, P = 60 kN, and w= 40 kN/m. Can someone please help, when I insert x=2m into the equation i derived for M, and then...

Homework Statement A uniform vertical beam of mass 40 kg is acted on by a horizontal force of 520 N at its top and is held, in the vertical position, by a cable as shown. a. Draw a free-body diagram for the beam, clearly labeling all of the forces acting on it. b. Calculate the tension in the...

I was supposed to measure a beam at a far away worksite but after a series of unfortunate events, I wasn't able to. All I know at the moment is it is referred to as I55 beam. I searched for it using every combination of words I can think of but cannot find it. We normally don't use beam...

Homework Statement Homework Equations I do not know exactly. The Attempt at a Solution I honestly have no idea how to approach this.

So I am starting to learn for the final exam a bit early and I am trying to do this problem with a uniform beam which is reinforced with iron inside. I know how to calculate this if it wasn't for the reinforcement within the concrete. I know that the purpose of the iron reinforcement is to...

I need to reduce the beam diameter of a laser I am using. I plan to do this by first passing the beam through a positive spherical lens with focal length f1 and then a negative spherical lens with focal length f2 and f2 < f1. By placing the lenses so that the two focal points overlap I will have...

I am trying to find the width of a square hollow structural member that can withstand the forces above. However, my calculations are showing me that a square hollow aluminum tube of 4 mm by 4 mm with a wall thickness of 1/16 of an inch would be adequate, which I don't believe. Is anyone able...

Homework Statement At the aquarium where you work, a fish has gone missing in a 10.5m -deep, 9.45m -diameter cylindrical tank. You shine a flashlight in from the top edge of the tank, hoping to see if the missing fish is on the bottom. What’s the smallest angle your flashlight beam can make...

Hello So I've done some calculations, I'd like to see if my stuff is right. Thanks :) Please view attached http://i.imgur.com/AfMZyr0.jpg area = (pi)(9^2) = 254.46 Cos53.13=15/CG CG=25kN Normal stress = 25000/254.46 =98.25