Shape Definition and 638 Threads

  1. Jason Chen

    Shape of vortex electric field line in a rectangular metal

    We know that,the shape of electric field line in a cylinder under varying magnetic field is circle,and I wonder,what's the situation if it is a piece of metal with rectangular cross section? I think it might be something like superellipses.Can somebody tell me is it true or how to treat this...
  2. E

    How to know the shape of a specific location on Earth?

    How do you know the shape (land altitude, roughness, etc.) of a specific location on Earth through a satellite? For example, if a specific place is covered by clouds is there a way to know the shape of the ground at this specific point? I have read through the absorption spectra of the...
  3. H

    Hypothetical Shape of a Spacetime and Time Travel

    Disclaimer: I am an aeronautical engineer with a background in fluids. My knowledge of cosmology only extends to articles and things I read before I go to sleep. So, here is my question: I have though about time travel, as many other people have. Currently we think it may not be possible, as it...
  4. R

    Bridge Beam Shapes: Why Are They Different?

    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...
  5. G

    Transition dipole -- Line shape function

    I am confused with the classical approach of usage of a "transition dipole oscillation" in order to explain the broadening of spectrum of emission between energy levels. 1. If I understand it correctly then emission of photon is due to oscillation of a dipole consisting of an electron-proton...
  6. pdaniel

    Earth's Electric & Gravitational Field: Direction, Shape & Height

    Homework Statement Earth actually has an electric field of 1.0 x 10^2 N/C at its surface pointing toward the center. (b) Compare Earth's electric field and gravitational field in terms of i) direction ii) shape iii) how it changes as height increases. c) What is the largest mass that can be...
  7. Helios

    Hypervolume: Exploring its Quantum Shape

    Certainly particles are not shaped like anything. However shapes themselves are informative. If particles were spheres, then they would trace out tubes in 4-d. After this though, we have lost the particle, so we have to chop the tube back up to pieces. However this piece has now become a...
  8. S

    3d Shape with lowest drag coefficient subsonic ground level

    Hello, What shape has the lowest drag coefficient at ground level and at subsonic speeds (0-150kph) with the following dimensions? Width 60cm (at 45%) Height 120cm (at 45%) Length 220cm These dimensions will fit my motorcycle (not too narrow and not too long). I am thinking it would be a...
  9. nicolauslamsiu

    How shape of pattern affects the behaviour of light

    chameleon can change the colour of its skin by changing the structural arrangement of cell layers. I found someone said that the shape of patterns of particles can determine how the light behaves when striking the object. I wonder how it works?
  10. A

    Best possible shape for the input controller?

    My project involves tangible user interfaces. I have developed a game in which the input will be any squeezable object. The input will have force sensors in it & the user's squeeze will be converted to electrical signal & characters in the game will move accordingly. Mode of squeeze is by...
  11. A

    Current flow in infinite sheet, and shape of isocurrents

    I am trying to determine the size of a conductive 2-D sheet that has a specified degree of increased resistance (or reduced conductivity) compared to an infinite sheet. Imagine that electrons enter the infinite sheet and exit the sheet at 2 points which are 1 unit of distance apart and aligned...
  12. T

    Calculating Deflection & Mode Shape in 3-Segment Plate

    When buckling plate of both ends fixed, the deflection and the mode shape of the plate can be found from the equation: y=M(1-cos mx)/P. With this equation, the cross sectional area and the young's modulus of the plate is usually unchange. However, if the flexural rigidity of the plate is divided...
  13. Q

    The shape of what we can observe?

    On a previous thread I viewed I saw a video about the observable universe: Now if you skip to the 3rd minute, you will realize that the shape of the areas we have observed is shaped like "butterfly wings", why did we not map the two triangle-shaped spots yet, why? And why is it particularly...
  14. G

    Draw a Hexagon with Parallel Lines: 6-Sided Shape Drawing Homework

    Homework Statement The problem involves drawing a particular set of lines and analysing anything of interest. The steps are as follows: : Begin with a hexagon with standard notation. : Draw a line (T) that passes through point B and which is parallel to AC. : Produce the lines AD and EC...
  15. CMaso

    Shape of Universe - What would a very long stick do

    if it were extended out from Earth, was perfectly straight, and could be any length desired? If I understand the prevailing theories it would either A) Just keep going forever (assuming infinite mass were possible), or B) Seem to travel in a straight line as far as we could tell, but eventually...
  16. S

    Does a diffraction grating with a shape form fourier image

    i just wanted to get this cleared that a beam falling on a diffraction grating with a shape gives the Fourier images of the grating object which can be reobtained by placing a biconvex lens that would converge the rays and form a focussed Fourier image at its focal length and the image of the...
  17. Feeble Wonk

    Has There Been Further Progress in Shape Dynamics Theory?

    As a non-physicist, what little I have learned about Shape Dynamics theory is appealing to me in many ways. http://arxiv.org/abs/1105.0183 I offer this link as a starting point for the discussion, but I'm curious if there has been any further progress in the professional and/or academic ranks...
  18. P

    Shape of electromagnetic field

    hello what are the shapes that a magnetic (of electromagnetic origin, so that it will be able to vary in intensity and switch on/off controlled by electricity) can have? for example, can we create an electromagnetic in the shape of a cylinder of specific dimensions? ie. to produce an...
  19. A

    Macroscopic shape of rocket exhaust

    Greetings to everyone. I would like to ask how the shape of a rocket exhaust plume changes with distance, when the rocket operates in a vacuum. What I'm mainly looking for, is to see how large the diametre of the plume would be at a distance of ~20km from the nozzle. We're assuming an ordinary...
  20. Dean Whaley

    Can a 4D shape exist in our universe?

    Can a 4 spacially dimensional shape exist in our 3 spacially dimensional universe? Could one exist and we just cannot perceive like a 2D animal could think it lives on a flat plane yet it actually lives on a sphere or donut shape? And could our universe be a 4 spacially dimensional shaped?
  21. Spinnor

    "The Shape of Inner Space", Shing-Tung Yau, preview or $.47

    Searching for spinor info on Google books came up with some good basic reading on Calabi-Yau manifolds via the preview at, https://books.google.com/books?id=6N6j9dBlh-0C&pg=PA131&dq=what is a spinor&hl=en&sa=X&ei=9GKsVLGQEqKCsQTt14KADA&ved=0CCkQ6AEwAjgo#v=onepage&q=what is a spinor&f=false For...
  22. I

    Does the shape of a car produce lift or downforce?

    I have a few questions related to downforce in cars. Please forgive any fundamental misunderstanding of aerodynamics. Does the shape of a car, say a Volkswagen Golf, driving on a road produce lift or downforce? Is the Coanda Effect at play there? How does the height of the car above the ground...
  23. K

    Shape of a Bending Beam with P Applied at the Axis of Symmetry

    Homework Statement A beam (e.g. a steel liner) of a length L is bent between two supports, as shown in fig (a). According to the Euler column, the shape is a half period of a sine. Now, a force P is applied at the axis of symmetry - fig (b). What is the shape of the liner? y=f(x) Instead of the...
  24. K

    The geometric shape of parametric equations

    Hello everyone, I have another question mark buzzing inside my head. After the elimination steps of a matrix, I'm having some problems about imagining in 3D. For example, x=t , y=2t, z=3t what it shows us? Or, x=t+2, y=t,,z=t ? Or another examples you can think of. ( Complicated ones of...
  25. K

    Approximating Windshield Shape of a Car: Velocity at Points A & B

    Homework Statement [/B] The shape of a car windshield is approximated in the figure below; its length is 2.0 ft and height is 1.5 ft. Obtain an equation of the windshield shape r as a function of θ, r(θ), in the polar coordinate system shown in the picture. When the car moves at 55 mph...
  26. Smit

    Shape of Projectile: Elliptical Equation

    Can we derive the equation of a projectile to be elliptical.
  27. R

    Why is the Braking Coefficient - Slip curve of this shape?

    Hi all, I want to know the why the Braking force coefficient is increasing first and then decreasing with respect to wheel slip. I attached the graph for your reference
  28. K

    Question related to Bending Stress and Shear Stress of a I shape beam

    1. Homework Statement The beam ABCD with the cross section has pin connections at B and C and is subjected to a uniformly distributed load w. If the allowable bending stress is 150MPa and the allowable shear stress is 80 Mpa. ( Hint : the horizontal reaction forces at A and D are both zero)...
  29. CutThroatJake

    Shape of Galaxies: Explaining Spiral & Elliptical Structures

    This may be a stupid question but it has been bothering me for a while. Why do galaxies look the way they do in a spiral? If a typical galaxy is 100k light years across is can take that much longer before the light from the far side to reach the telescope. Unless it is face on of course. If...
  30. albertseng

    How do I calculate the deflection of an L-shaped pipeline with added loads?

    Hello, Uncle have one question. How to calculate the deflection of the upper flange if the pipe configuration is like the attached picture. How to include the weight of the pipe, can I assume it as the distribution load? And what if there is another load acting downward at the middle of the...
  31. P

    How Did Saartjie Baartman Influence Victorian Fashion?

    Read full paper by click here.
  32. G

    Spherical shape surface area calculation

    Homework Statement Homework Equations [/B] Surface area of sphere = 4*Pi*r^2, where r: is the radius of the sphere circleThe Attempt at a Solution Solution:[/B] 1. In terms of “r” and “R”, and the radius of sphere “S”, and “d”: Given that: · Surface area of both shaded area are equal...
  33. H

    What shape would produce the greatest electric field?

    Suppose you are given an incompressible material with a constant charge density. What shape would create the largest electric field at a given point in space? These seems like a calculus of variation problem, but I am wondering if there might be any clever trick. $$\vec E = \frac{\rho}{4 \pi...
  34. J

    Trying to cut a parabolic shape in sheet metal

    Hi, I am trying to cut a parabolic curve in a piece of sheet metal using a numerically-controlled cutting machine (basically a very hard rotating router blade). The router blade is 10mm diameter. I want to achieve a parabolic cut in the sheet metal that adheres to the formula y=x^2 The...
  35. H

    Electromagnetism and theoretical shape of a photon

    Hello all, I have a few questions and a few thoughts I think I understand that according to einsteins theory of relativity, wavelengths can be perceived differently when traveling at different velocities comparatively to when it was emitted. i.e. if something traveling close to the speed...
  36. C

    Derivation of Planck's law and the shape of the cavity

    When Planck's law is derive a cubical cavity is often used (for example in: http://disciplinas.stoa.usp.br/pluginfile.php/48089/course/section/16461/qsp_chapter10-plank.pdf) However, the result is applied generally. But in general, it seems like the wave lengths of the standing waves will...
  37. B

    How to arrange given resistors in a given shape to meet target value?

    Homework Statement I have available resistors of 5 different values (10kΩ, 22kΩ, 47kΩ, 100kΩ and 220kΩ). How can I choose a combination of these resistors that will create a total resistance of 35kΩ in a U shape (using 5 resistors)? See attached picture of 'U' to get a clear picture of the...
  38. O

    Distance from arbitrary shape so we can treat it as a point charge

    Homework Statement Non-uniform charge distribution over a randomly shaped object. This object will fit inside a sphere centered on the origin with radius r. What is the minimum distance from the origin that we can assume such that we can treat the electric field as if it were generated by a...
  39. N

    Why can a smooth function be described with fewer terms in a Fourier series?

    Hi! I am taking a second look on Fourier transforms. While I am specifically asking about the shape of the Fourier transform, I'd appreciate if you guys could also proof-read the question below as well, as I've written down allot of assumptions that I've gained, which might be wrong. OK...
  40. G

    How to calculate that shape inside volume?

    Dear everybody here, please i need help at that attached image of round shape as shown, my questions is what is the formula which used for calculating the volume of that shape?, the cylinder of D1, and D2, , easily can be calculated by (Pi/4*D2*L), so how about in the middle? will...
  41. S

    Teardrop shape for muffler? Any equations for this?

    Hi, all. I have an idea I want to try out for a muffler design on a single-cylinder engine (174.5 cc liquid cooled fuel injected scooter engine). My idea is to create as free-flowing a muffler as possible (lowest backpressure) while still making it as quiet as possible using the concept of...
  42. A

    Could the Offspring of a Human and Shape Shifter Possess Shifting Abilities?

    I am currently working on a story, and would like to pose a Theoretical Genetics Question. If a non-human shape shifter takes human form, then meets and falls in love with a human being… Would their offspring be shape shifters as well? For the sake of this question we will make four basic...
  43. C

    Gravity force: Isn't it just the shape of space?

    Isn't the force of gravity just a result of the shape of space as it is affected by masses within it? Why is it believed that it is a force associated with theoretical force particles "gravitons"? I can understand that the electric or magnetic force is a product of particles with fundamental...
  44. X

    Catenary shape of a towed underwater cable

    Hello, I'm designing a towed underwater vehicle (towfish) and I am having trouble with determining cable tension at the length of the cable at given depths and speeds. I have estimates of vehicle drag at speeds up to 4 m/s and the vehicle weight in water is known. Its really just the...
  45. I

    What determines the starting point of a bending moment diagram?

    In the bottom left, why does the BM diagram start at -4kNm rather than 4kNm? I understand that if you make a cut you yield this result but if you don't make a cut how would you know whether it starts at -4kNm or 4kNm? Thanks
  46. I

    A few questions about size and shape

    When science makes observations on the universe and combines those observations with common sense, at least for me it generates extremely peculiar results. For example if the universe is infinite, does this exclude the 'multiverse theory'? After all if an object is infinite, then that object is...
  47. B

    Clepsydra shape using Fourier series

    Our Fluid Mechanics professor gave us a challenge: to find the shape of a vessel with a hole at the bottom such that the water level in the vessel will change at a constant rate (i.e. if z is the height of the water in the tank dz/dt=constant). I presented a solution assuming that the vessel...
  48. H

    The shape of water poured out of a glass

    Why does water get that shape when poured out of a glass, almost like the nodes and antinodes of standing waves in a string? Also, the 'parts' of water (For want of a better term) seem to be perpendicular to each other, alternatively. I really think I'm doing a bad job of explaining this, if...
  49. D

    Shape of Airfoil: Analysis & Design

    Homework Statement See attachmentThe Attempt at a Solution Im not sure how to solve c and d...
  50. G

    MHB Calculating a Zipline's Shape: Seeking Advice to Start Learning

    Hi I want to understand how to describe the shape of a zipline given a certain mass at any point along that line and a difference in height of the Initial anchor point to the final anchor point. I know that I don't know enough calculus to be able to work this out, but what I would like from...
Back
Top