Beams Definition and 274 Threads

  1. B

    Where Did I Go Wrong in Solving This Physics Problem?

    Appreciate if someone could take the time to look at the following problem, my answers, and can point out where I have went wrong. Also, part 4, I think more info. is needed to determine this, but I may be wrong. Anyway, here goes: A hoist motor is attached to a support beam as shown in the...
  2. R

    Structural analysis influence lines in beams

    Homework Statement http://antishift.org/image.php?id=16122&size=medium Homework Equations Static Equilibrium equations: since most of the supports are rollers, only y-forces are considered as well as moment equations. I'm pretty sure E and F are hinges so there are no moments around E and F.The...
  3. R

    A (hopefully) easy question to answer about cantilever beams

    Hi guys, just wondering if you could help me out? For a standard rectangular cross-section cantilever beam with a concentrated end load how do i work out the top surface stress at a point along the beam? do i just use sigma=My/I where y=half the depth of the beam and M=end load * distance...
  4. J

    Solve Cantilever Beam: End Load 20kN, EI=40KNm^2, Length 0.25m

    Homework Statement A cantilever beam carriers an end load of 20kN and has an EI value of 40 KNm^2. If the beam is 0.25m long, use intergration to determine the slope at the free end of the beam? Homework Equations I know from a handout I have that the fudamental equation to...
  5. N

    The Unruh effect and light beams

    According to the Unruh effect, an accelerating observer will find himself surrounded by a "warm bath" of particles (see http://en.wikipedia.org/wiki/Unruh_effect ). Now consider two observers,A and B, one accelerating (B) and the other (A) in constant motion (or rest). Let the accelerated...
  6. B

    Calculate Deflection of Beam Under Point Load

    How do I calculate a deflection under a point load?
  7. J

    How Do You Calculate the Energy of an Electron Beam in an Electron Gun?

    Hey guys Apparently I have to know how to find the energy of accelerated electron beams for a test, and I'm not sure how. Any help? I'm assuming it's talking about electron guns: I think this consists of a heated cathode which emits electrons via thermionic emission, and an anode which...
  8. J

    Discovering the Energy of Accelerated Electron Beams by Jonty

    Hey guys Apparently I have to know how to find the energy of accelerated electron beams for a test, and I'm not sure how. Any help? I'm assuming it's talking about electron guns: I think this consists of a heated cathode which emits electrons via thermionic emission, and an anode which...
  9. A

    Intensity and Interference of Light Beams

    i have to do a physics assignment and i got stuck at this quesion hope u guys can help. An interference pattern is formed on a screen by the superposition of two coherent light beams, one of which has four times the intensity of the other. What is ratio of maximum to minimum intensity in the...
  10. Ivan Seeking

    What Mystery Shrouded the 1979 UFO Encounter with Deputy Val Johnson?

    http://www.grandforks.com/mld/grandforks/news/14757502.htm
  11. J

    What Spray Could Make Laser Beams Visible?

    Hello, I was wondering if anyone has ever seen a movie where some people are robbing a bank or art gallery, and they spray something to make the laser beams show. Does anyone know what type of spray could do this? I have tried google, and I didn't know if this is the right place to ask...
  12. Astronuc

    What Are the Different Types of Beam Cross-Sections?

    Beam cross-sections http://www.efunda.com/math/areas/Common_Cross_Section_Index.cfm Standard beams http://www.efunda.com/math/areas/IbeamIndex.cfm About 10 or so free look ups. Requires subscription Monthly (recurring till cancelled) $6/month Student $36/year Professional...
  13. P

    Complete EM Field of Gaussian Beam: References & Pointers

    Does anyone have any references or pointers to the complete electromagnetic field of a "Gaussian Beam"? By Gaussian, I mean that for a beam propagating in the z direction, a cross-section of the beam in the x-yplane has |E| = k exp( -(x^2+y^2)/w^2 ) see for instance...
  14. C

    Exploring the Interests of Working with Steel Beams

    How does one work just out of interest? I use it when loading a steel beam to see the strain induced in the web of a chanel section. can't figure out how it would work
  15. J

    Why Is the I-Beam Shape Optimal for Moments of Inertia?

    I recall that the shape of an i-beam is near optimal because of its moment of inertia. Does any have a reference that shows this, with explanation?
  16. P

    Calculating Max Deflection of Simply Supported J Section Beam

    If i have a simply supported J Section beam, when I'm calculating the max deflection, what value of I do i use? I have already had to calculate Ix, Iy and Ixy. I would imagine that as deflection occurs along the y-axis that i would use Iy. Or do i use Imin? I have already calculated...
  17. P

    Protecting Your Eyes in the Laser Lab: Tips and Precautions

    Suppose I have an arbitrary amount of diode lasers, all of identical construction and abilities. Assume I can determine/control the polarization of each diode beam. Does anyone know how I can increase the amount of photons in a single laser stream via combining all the diode beams without...
  18. C

    Beams of light and wave effects .

    Beams of light and wave effects... Let us first think of a ripple tank and how this is used to demonstrate diffraction nad interference- this is one wave front so when passes through small gap curves the wavefront, spreads the wave out and thus causes diffraction. We often use this analogy to...
  19. N

    Theory Of The Ionization Of Gases By Laser Beams

    THEORY OF THE IONIZATION OF GASES BY LASER BEAMS could anyone help me about is theory ican't find it plase iknow i ask a lot :blushing: but sometime my mad don't work enough :confused:
  20. G

    Matter Beams: Exploring the Possibilities and Limitations of Particle Streams

    I have a few questions about matter beams. 1. Is a matter beam simply a stream of particles? Can I make an alpha, electron or neutron beam by simply encasing a radioactive source in lead, punch out a hole and filtering out the rest? Can air rushing out of a tire in a vacuum chamber be...
  21. M

    Balancing Two Uniform Beams: Calculating Forces & Angles

    Two identical uniform beams, each having a mass of 4 kg, are symmetrically set up against each other on a floor with which they have a coefficient of static friction µ = 0.609 . a) What is the minimum angle the beams can make with the floor without falling? b) For the angle calculated in...
  22. ShawnD

    How Does Temperature and Applied Force Affect Stress in Different Materials?

    Look at this picture http://myfiles.dyndns.org/pictures/stress.jpg The top and bottom bars do not bend at all. The setup is taken outside where the temperature is 70C colder then a force of 100kN is applied to the top. Find the stress in each of the 3 columns. The area of each aluminum...
  23. Gara

    Interference of Light: Perpendicular Beams

    what happens when two beams of light pass through each other perpendicular to each other??
  24. Hamish

    Electron beams and an inertial frame problem

    I wasn't sure whether to post this in the classical or relativity section. While pondering something I found an embarrassing gap in my knowledge. I can't quite get my head around this problem and I need a fresh perspective. Consider two beams of electrons moving parallel to each other. The...
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