Shape Definition and 638 Threads

  1. N

    Chain shape (Euler-Lagrange equations)

    A chain with uniform linear density d and length L is tied at two ends to the ceiling. How to find its shape using Euler-Lagrange equations? (I know it can be done with other methods, but I want to know how to do it using E-L).
  2. P

    What is the shape of an electron?

    What does an electron look like? What is it made of? It has to be made of something? Can we/Have we been actually able see an electron?
  3. Holocene

    Exploring the Shape of a Flat Universe

    I just want to make sure my understanding is correct. In a "flat" universe, the total density of the universe matches the "critical density". As a result, the universe will expand forever, and never "fall back" into itself. The shape of a flat universe, as the name suggests, is flat like a...
  4. H

    Can These Points Form a Square in Geometric Constructions?

    let ABDE and BCGH be squares lying outside the traingle ABC. The centres of these sqaures are P & Q respecitvely, and the midpoints of the line segments AC and DH are R & S respectively. Show that the points P,Q,R,S are vertices of a square? any ideas on how to do this please? the only hint i...
  5. T

    Does the shape of the curve, that is produced in space by a mass, have a name ?

    I have been reading an article about a theory of gravity that involves space being curved or warped. An example was given where a heavy weight, representing the sun, is placed in the centre of a trampoline, and a golf ball, representing the earth, is caused to circle the centre of the...
  6. J

    Stargazing Liquid Mirror Telescope: How to create a parabolic shape

    I recently read about a proposed liquid mirror telescope to be constructed on the moon. My question is one of mechanics, hence this not being in the astronomy section. My question is regarding the shape of the surface of a rotating liquid. The design will have a dish containing a thin layer...
  7. P

    Symmetry and shape of elementary particles

    Hi! Although nobody can see the shape of elementary particles, we always assume that their shapes are symmetrical, for example, sphere. Why? Is the symmetry a law? Otherwise, are there any other reasons? Patrick
  8. M

    What exactly is the solenoid shape? Is it just the coil?

    What exactly is the solenoid shape? Is it just the shape of the coil with the core inside or do they refer to the shape of the magnetic field surrounding the coil?? Is this the solenoid, just the coil? Or are they talking about the magnetic field that surrounds the coil?
  9. N

    Is Our Universe Infinite or Spherical?

    Lets get a bit of brain-storming going... What shape is the universe? Is it infinite in all three dimensions of x, y, z ? Is it spherical?
  10. W

    What do I need to put myself in shape for the Putnam competition?

    I'm not sure I even have enough time to prepare (a summer is very short). But still, I want to give myself a shot so I'm asking; what do I need to do good on the Putnam contest? Now I know this may sound like asking a question like "what do I need to one day walk on Mars?". So my real question...
  11. S

    Shape of Orbitals in Periodic Crystals: Hybridization and Energy Bands

    I asked myself how the orbitals in a solid look like. Assume a crystal with a periodic structure, e.g. NaCl. The electrons in the crystal have energys according to the energy-band-model. Every band consists of that much discrete energy-levels that you might nearly call it continous. I know that...
  12. S

    What Shape is this Paper Lamp?

    Hi, I built this paper lamp and am trying to figure out what shape it would be classified as (dodecahedron, etc.). I've attached a picture of the shape, thanks for your help.
  13. R

    Discovering the Shape of the Universe: An Elegant Inquiry

    I would just like to ask a very elegant question. What is the shape of the universe?
  14. V

    Boeing How Does the Boeing 787's Wing Shape Enhance Flight Dynamics?

    There is a photo of a boeing 787 at http://en.wikipedia.org/wiki/Boeing_787 Is this a new wing shape? It looks very curved both in the plane of the wing and for a dihedral.
  15. B

    What is the force exerted on cylinder A in a V-shaped trough?

    Homework Statement Ok, my problem has 3 smooth homogeneous cylinders(A,B,C), which are stacked in a V shaped trough.(the cylinders...look more like circles) are also all touching each other and each is touching a surface of the trough. The trough angles are Left = 30 deg and right = 45 deg...
  16. N

    Understanding Stoke's Theorem: Does Surface Integral Depend on Shape?

    i'm trying to understand stoke's theorem and am having trouble seeing whether the surface integral for a given surface changes with any change in its shape, or if it only changes depending on the cross sectional area perpendicular to the direction of the vector field. can anybody help me out?
  17. E

    What are the shape of nucleons and quarks?

    When one of the quarks was discovered, I was in high school, and I said quarks are not spherical balls of mass. How could nucleons also be spheres if 3 quarks make up a nucleon?! I said atomic and subatomic particles have a poorly defined shape and something of a lack of material substance...
  18. E

    Understanding and Managing Curly Hair: The Role of Hair Bulb Shape

    My hair is so curly, and I hate it so much.:frown: I wouldn't mind if it was wavy but it's curls a like 1cm length. And when dry it's especially hideous. I did a little research and found out that in curly hair the hair bulb inside the scalp is hook shaped, and in straight hair it's straight...
  19. T

    Predicting the Shape of Complicated Functions

    This isn't a homework question-- it is a general question about curve sketching in multivariable calculus. In order to draw graphs in 3D, we use level sets, then-- if the level sets are something "nice" like circles or parallel lines-- we take a cross section when y=0 and then transform the...
  20. K

    Calculating Phonon Gas Density of States and Unit Cell Shape

    Let's suppose we have a Phonon gas in 1-D then: - density of states g(k)=A/ \frac{ d\omega (k)}{dk} (i don't remember the value of constant A sorry.. :-p :-p ) - The Schroedinguer equation (NO interaction) would be: H_TOTAL =\Sum_{i}\frac{P^{2} _{i}}{2M}+ \sum_{i}B\omega ^{2}(k)...
  21. L

    Derivatives Affecting Shape of the Graph

    I have the following question: h(x) = (x^2-1)^3 a) Find the intervals of increase or decrease b) Find the local maximum and minimum values c) Find the intervals of concavity and the inflection points d) Use the informatin from parts (a)-(c) to sketch the graph Now I figure a good way...
  22. ر

    Exploring the Shape of Spacetime

    hi every one I'm asked about the spacetime and his shape is spacetmie like the sea or waht? thank for everyone
  23. T

    Salt Crystals: Shape & Structure

    What is the shape of salt crystals.??
  24. A

    Shape of the Universe: Evidence for Expansion in a Single Direction

    How is it not possible that the universe is shaped like a sphere? What evidence do we have that shows it is expanding in a single drection or some variation that of? I recently heard that the origonal spherical theory doesn't work because of the increased speed of expansion, what I...
  25. H

    The shape of Copper Tetraamine Complex

    Why is Copper Tetraamine Complex a square plane? Shouldn't it be tetrahedral since there is only four bond pairs?
  26. C

    Atom Shape: Experiments, Spheres & Cubes in Physics

    Hello, Is there any reason to believe an atom, say Hydrogen, is spherical via experiments, or is this merely a model for us to visualize with? Furthermore, can one prove that an atom is not a cube? Finally, is there any model in physics that can account for how a photon is emitted...
  27. S

    What causes moon to change its shape?

    Ok this is really funny. This is a really simple question and I used to know it but the more complicated things I learn, the more doubt I have on my foundation. So what is it that causes moon to change its shape?
  28. S

    Shape-Changing Robots: Exploring Feasibilities

    I once had a chat with a Prof. at school, who talked about amoeba like robots. Since I am not so much into robotics, but nevertheless found the concept very amusing, I'd like to get some feedback on what are the feasibilities of the ideas below (all of which are just random thoughts supported by...
  29. S

    Voyager 2 Detects Odd Shape of Solar System's Edge

    http://www.space.com/scienceastronomy/060523_heliosphere_shape.html So if it does get will we still have contact with it
  30. A

    Is the Shape Operator Always Symmetrical?

    :confused: Please, help me to solve that task related to Shape Operator. We have surface S and its normal N. Alse we have surface patch r : U -> S in local coordinates r_1, r_2, ..., r_n. Shape operator (Weingarten Linear Operator) is defined as follow: L_p : T_{r(p)}S -> T_{r(p)}S, where...
  31. P

    That is the integral that I would use to find the volume of the solid.

    q: (set up the integral that you would use to find the volume of the solid described, evaluate the integral) The region below the plane z+y=1 and inside the cylinder x^2+y^2 equal or less than: 1,0 equal and less to z equal and less to 1 this is what i have been trying: tried -sqrt1-x^2...
  32. D

    Is the Universe Really Spherical? And What Lies Beyond?

    From what i heard(from my brother by the way), Einstein once predicted that the universe is spherifical( i don't know if it is true or not), is the universe really spherical?? if so, then what lies outside our universe??
  33. A

    Proving ellipse shape of earth orbit?

    hi, i am secondary student, can anybody help me to find a site in proving ellipse shape of Earth orbit? and also those site which help you in understanding Principia?
  34. W

    What Is the Shape of the Universe?

    Does anyone know what shape the universe is? I.e. a sphere, or an eliptical sphere? and is that the observed shape of the shape after relativity calculation?
  35. D

    Integration has to do with a square shape

    Hi I have mentioned yesterday some integrals that have a circle in the symbol... I think the integration has to do with a square shape... What is this? Where i can find more info? Also do u know what anadelta means?
  36. E

    Why Do Galaxies Form Spiral Shapes?

    how can this be explained?
  37. S

    Toroid shape Electro-Mag question

    I have a difficult probelm to solve: There is a dougnut shape (toroidal coil) with N turns of wire wrapped around it. Current I flows in the wire. THe cross section of the 'doughnut' is square with height h. I am meant to use ampere's law to prove that the magnetic field at a radius r from...
  38. S

    Why are our planets and galaxy in a plane shape?

    Why are the planets in our solar system spread out in a plane instead of being more randomly spread around the Sun? And why is our galaxy in the shape of a plane instead of all the stars in our galaxy being more randomly spread around the middle of our galaxy? Thanks,
  39. S

    Magnetic Field of a long wire bent into a shape

    a) A long wire is bent into shape as shown in the figure without he wire actually tocuhing itself. The radius of the circular sectio nis R. Determine the magnitude and direction of B at the cneter C of the circular section when the cirrent i is as indicated. Well i think that due to the...
  40. siddharth

    Exploring Precessing Ellipses: Showing How F Changes Orbit Shape

    Suppose that the force of attraction between the sun and the Earth is F = GMm(\frac{1}{r^2} + \frac{\alpha}{r^3}) Where \alpha is a constant. Show that the orbit does not close on itself but can be described as a precessing ellipse. Find an expression for the rate of precession of the...
  41. A

    Centrifugal Force and shape of water

    "Centrifugal" Force Say you have a cylinder of radius r with πr2h liters of water in it. If you put it on some sort of turntable and spin it with an angular velocity ω, is there a way to tell what the shape of the water will be? I mean, if you look at the cross section will you be able to...
  42. S

    Why do ripples on water appear circular?

    Why are ripples on water only circular in shape? Why arent they of the shape of the object dropped in them? Like triangular or square?
  43. S

    Exploring the Shape of the Universe: A Fascinating Look at Recent Research

    This recent paper is interesting:http://arxiv.org/abs/physics/0509171 It has some interesting images, and it offers some conceptual thinks.
  44. C

    Find equation for shape of reflecting surface

    Here is the question, I just need verification, don't know how to make the fancy formulas here so bear with me... Consider a reflecting surface that produces parallel rays from a point source of light. The axis of the mirror lies on the x-axis which passes through the mirror at x=y=0. The...
  45. wolram

    Staying in Shape: Tips for Keeping Fit

    How do you keep fit ??
  46. T

    Can anyone solve this shape of a string puzzle?

    Can anyone solve this... "shape of a string" puzzle? Let's say there is an infinite massless and elastic string, which laid horizontally and one of the ends is extended to infinite distance. The string is "pulled" thoroughly and somehow, so that there is a tension T along it. There is a...
  47. S

    Shape Shape-shifting strings solids, liquids, and gasses

    For your thoughts... a theory of mine... A Method by which shape shifting strings may explain: 1. Plasma 2. Hydrogen 3. Helium 4. Neutrons 5. Gasses 6. Liquids 7. Solids Consider the following: If a string, was a string, in shape, in only one STATE of its existence, then one...
  48. Y

    Extra Dimesions (the Calabi-Yau shape)

    Can anyone give me more insight on this Topic... The mathematics of this geometrical shape is quite complex..,, its hard for me to imagine these shapes (infact i find it very difficult to imagine space wrap with the three spatial dimesions, its easier to imagine them with two dimesions). and...
  49. P

    Best Shape Around Valve Guide for Engine Flow

    Hello May you tell me what is the best theoretical shape around a valve guide for best flowing in an combustion engine ? best regards Philippe
  50. M

    Find The Area Of A Shape In Form Of A Star

    Is It Possible For One To Find The Area Of A Shape In Form Of A Star,i Am Noi Good At Latex Else I Would Have Drawn It,shapes Like The Star,with More Than 5 Pointings
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