Shape Definition and 613 Threads

  1. C

    Michelson Interferometer - Fringe Shape

    Hi all Edit: The reflecting side is the right side of left slab Please look at the pic above ... The light from source splits at left slab and goes in 2 directions and come back to interfere. From figure, it is obvious that path diff. in slabs for both rays is 0 and only path diff...
  2. M

    Shape Tealight Flame - Simple Sphere & Cylinder

    Hi, I'd like to ask, if its possible to shape a fire. Would it be possible on tealight ? I don't want complex shapes just simple ones like sphere, cylinder... Thanks
  3. 1

    Hard to find bubble rise paper/bubble shape determination

    Hi all. I'm looking for a paper that I've seen referenced in a couple of articles I've been reading. The paper is O. M. Kiselev, Determination of gas-bubble shape in axisymmetric flow of fluid, Zh. Prikl. Mekhan. Tekh. Fiz., No. 3 (1963). The English name of the journal is Journal of...
  4. H

    How to Find the Centroid of a Composite Shape?

    Homework Statement As part of a test I was given an irregular shape to find its centroid. It was a rectangle with a right angled triangle on its right side (I don't have a picture to upload for ye unfortunately). Homework Equations dA=y.dx X(bar)=intrecal x.y.dx Y(bar)=intrecal y^2/2.dy The...
  5. P

    How Does General Relativity Explain Earth's Shape and Gravity?

    I have read that at sea level gravity is the same everywhere on the surface of the Earth. I have also read that motionless clocks at sea level will stay synchronized. It seems to me that this should be a consequence of general relativity. If one instead uses Newtonian gravitation then...
  6. Vorde

    Big Bang Theory and Shape of the Universe

    Is the big bang (referring to the well-established theory of post-Planck time evolution) compatible with any model of a finite universe that isn't spherical in topology? It seems to me that the big bang theory requires that the universe be finite in volume and the only way that seems feasible...
  7. A

    How Do You Analyze a Charged Shape Described by a Mathematical Function?

    The Image has all the details: http://img38.imageshack.us/img38/3448/question3p.jpg Uploaded with ImageShack.us I honestly I have no Idea as to where I should begin. Any hints on how to get started?
  8. K

    Shape of Standing Wave at Maximum Kinetic Energy

    What is the shape of the string at time=0? This is my wave: y(x,t)=(0.03)sin( (3π/4)x)cos(200πT) I assume that x=vt and replace in sin. Then sin(0)=0 and then the shape of the string is a line. Is this correct?
  9. T

    What Shape Does a Catenary Shadow Form on a Cylinder?

    I saw a shadow of a catenary (or close enough) on a cylinder and wondered about the shape. Specifically, it was a powerline strung between 2 utility poles, and the sun angle would have been around 45 degrees or so, and the cylindrical grain bin was between and north (I am in northern...
  10. H

    Rainbow Shape: Why Is It Always an Arc?

    why is rainbow always an arc?
  11. P

    Question about the shape of the earth

    Why is the Earth not perfectly round
  12. M

    The shape of black holes and their surroundings

    Hi Guys, Just a thought, if a job of a black hole is to suck everything in it's surrounding to nothing-ness. Then why are the there examples of black holes with jet streams flowing away from their axial poles? Apparently the Earth's gravity field is weaker at the equator, so why does...
  13. 5

    Wire cut to shape circle and square so total area is maximum or minimum

    Homework Statement A piece of wire 40 cm long is cut into two pieces. One piece is bent into the shape of a square and the other is bent into the shape of a circle. How should the wire be cut so that the total area enclosed is a (a) maximum and (b) minimum? Homework Equations Area...
  14. R

    The shape of space-time around a star

    Gravity around star is often depicted as the curvature if spacetime or a 'dimple" in a flat sheet. What would happen to space-time around a star if the star were to instantly disapear? Would the fabric of space time snap back to flat space or would it reverberate, expanding then contracting...
  15. D

    Effect of lunar/solar gravity on shape of earth

    In Gamow's short book 'Gravity' he describes the effect of lunar gravity on the earth, in particular the seeming paradox that the oceans, in response to the tug of the moon, swell both in the direction of the moon and on the opposite side as well. He resolves the paradox by explaining that...
  16. A

    From every angle, what is the complete shape of a black hole?

    Is it shaped like a tornado, or a sphere, or is it flat like a disk? If there was a way to view a black hole, dimming the brightness around it to get a clear look, what would be its full shape if you could view all around the outside of it from every possible angle?
  17. A

    Motion of electrons in orbitals and shape of orbitals

    Why don't electrons move only along the surface of orbitals? Moreover, how do electrons move within orbitals, random movement or do they follow a definite path? In a p-orbital, does one lobe consist of only one electron? Why is the p-orbital dumbbell shaped and not spherical?
  18. T

    Gas equation of state and shape of container

    Does the equation of state of a gas of interacting particles depend on the shape of the container they are in? For instance, if the interaction force is gravity (a central force) and the particles are in a spherical container, then it seems reasonable that the pressure on the wall of the...
  19. P

    Into what shape does an orbiting sphere get distorted by tidal forces?

    I'm having trouble imagining how an orbiting object would get distorted by tides --- in the first instance, say, the distortion of an initial uniform dense ball of coffee grounds (of the sort John Baez likes to imagine in his web pages). I know and understand why, if it were infalling radially...
  20. T

    Geometric shape of Minkowski space

    So, suppose for visualization there are only two dimensions: ct and x. Now if the metric where Euclidean, we could visualize this space is a simple plane. What would be the shape of the "plane" when the metric is +1, -1 (Minkowski)? Is it somehow hyperbolic?
  21. M

    PVC End Plug and Tube shape retention under heat and force?

    PVC End Plug and Tube shape retention under heat and force?? Hi, I'm Mai from one of the semiconductor company. I'm in charge in supplier quality enginnering. I have an issue happened in my customer side where, whenever they received the unit from us the unit will spill out from the packing...
  22. T

    Can measurements of red shift be affected by the shape of spacetime?

    I have read on some threads that there are other possible shapes for spacetime and I wondered could any of these spacetime shapes, or their change over time, affect our measurement of red shift? Also does the matter density at the location where a photon is emitted relative to our own...
  23. Femme_physics

    What is the name of this shape with unequal sides?

    http://img839.imageshack.us/img839/4557/imagegrn.jpg What is this shape called? I thought a "pentagon" but since all sides aren't equal it can't be
  24. I

    Could the Shape of the Universe be Explained by Black Holes and Supernovas?

    I'm a college student in New York and I've been doing some thinking lately. Although mathematics is unfortunately one of my weaker subjects, I was wondering what you all might think of this idea. I've been reading about black holes and looking at different ideas of what the universe may look...
  25. S

    Projectile motion parabola shape

    why the projectile motion's graph distance against inclination angle is parabola shape? ...thank you
  26. B

    What Factors Influence the Spinning Patterns of a Coin?

    Hi all, Im new here so please be gentle. Whilst in the pub last night a game was started with spinning a coin. We got to the point where we could all spin the coin with our hands in a circle around the salt shaker, about 3cm diameter. We then moved on to the pint glass and achieved that...
  27. L

    Does the shape of the Universe contribute to the gravitational path?

    Reading just enough to be dangerous concerning Riemann geometry, choices of geometry regarding the shape of the Universe, etc., and the geodesic mappings to different geometric models (flat, spherical, and hyperbolic), I have an unanswered question in my mind. Acknowledging the affect of large...
  28. C

    What is the shape of a photon's electric and magnetic fields?

    Greetings, I see graphs of the amplitude of a photon's fields over time, but no illustrations of the shape of the field at any instant in time. Are the fields confined to planes like they look in the graphs? Or do they extend in three dimensions like the field around a magnet? Thanks
  29. J

    Conversion from 'Shape*' to non-scalar type 'Shape' requested

    I get this error and I don't know how to get rid of it... I declared the Shape struct typedef struct { int tShape; int centerX; int centerY; int sizeX; int sizeY; int color; int filled; } Shape; When I try to send a Shape struct called shape to a...
  30. K

    Best Fit for 2-D Shapes in Larger Shape?

    Hi, my first post here and I'm not sure I'm in the right place or that I use the proper terms so please bear with me. I'm a programmer by trade, and I'm working on a project whereby I need to arrive at the best fit for a set of 2-D shapes fitting within a larger shape. Mostly we're dealing...
  31. W

    Mysterious Red Shape on Google Earth

    I was looking around the skymap on google earth, and I saw a strange red shape, so I zoomed on it and found this, It looks like some sort of star and a red thing shooting some jet, but I have no clue, never seen anything like this in any of my books.
  32. P

    Find Centroid of Shape: X & Y Dimensions from Point O

    Homework Statement CALCULATE POSITIONS OF THE CENTROID OF THE SHAPE SHOWN BELOW GIVE DIMENSIONS FROM POINT O ALONG THE HORIZONTAL X-DIRECTION, AND THE VERTICAL Y-DIRECTION. [PLAIN]http://img402.imageshack.us/img402/738/unledgj.jpg Homework Equations The Attempt at a Solution I...
  33. marcus

    Shape Dynamics and GR linked (Gomes Koslowski)

    http://arxiv.org/pdf/1101.5974 The Link between General Relativity and Shape Dynamics Henrique Gomes, Tim Koslowski 14 pages (Submitted on 31 Jan 2011) "We show that one can construct two equivalent gauge theories from a linking theory and give a general construction principle for linking...
  34. I

    Shape of graph polynomial to the fifth degree

    Hello my friends, I have this problem and would appreciate someones help: Determine all intervals where the following function is increasing or decreasing. F(x) = -x^(5)+(5/2)x^(4)+(40/3)x^(3)+5 Solution To determine if the function is increasing or decreasing we will need the...
  35. Femme_physics

    I don't believe that an area/volume can change based on a change in shape

    And I know that I'm being extremely stupid in saying that. I know I'm mathematically wrong. Please convince me otherwise. It doesn't make sense to me that if I change the shape of something it can alter its area/volume. I always thought these remain constant. Is there any experiment that I...
  36. R

    The Shape of the Universe, and General Relativity

    Hello! I'm trying to get my head around general relativity at the moment...(!), and there's one aspect of it that's really causing me a lot of kerfuffle. I understand that in an appropriately sized local inertial frame, the laws of special relativity occur. On those scales the curvature...
  37. K

    What is the spiral shape produced by an attractive (1/r^2)sin(theta) force?

    I was wondering what shape a (1/r^2)sin(theta) force would produce between two bodies. theta = angle between the distance between the two bodies and the velocity vector (90 degrees for a circular orbit).
  38. B

    How Do You Find the Centroid of a Structural Shape with C-Beams?

    I have a problem trying to find the centroid. I have a plate that is 8in wide and .5 in thick. Then 2- C beams (C8x11.5) placed at each end of the 8in beam with the tips facing each other. They do not go beyond the 8 inches. So it's like a U as an example with the tips facing each other. I...
  39. K

    How to calculate Young's Modulus on trapezoidal shape ? Can't find the answer .

    How to calculate Young's Modulus on trapezoidal shape ? Can't find the answer... Hi guys. I'm really stumbling over this question. If I'm trying to calculate the Young's modulus of a specimen that is being compressed from the top, but the contact area on top is smaller than the bottom...
  40. T

    Exploring Shape Resonance in Air: Oxygen and Nitrogen

    Greetings. I've been reading papers on plasma kinetics and have come across the term "shape resonance" a few times when describing peaks in electron impact cross section (function of energy). I have seen calculations attempting to explain these for atoms like helium but I'm not sure how close...
  41. T

    Lift from airfoils, decrease lift as a result of curved shape at large angles?

    Hi, in my point of view lift is created as a result of two pressures, the static and the dynamic. The dynamic pressure is the dominating creator of lift at large angles of attack. For example a flat plane at 45 degrees will create lift. The static pressure is the dominating creator of...
  42. X

    What is the Shape and Size of a Pixel and How Does it Affect Screen Resolution?

    A pixel is said to be an intersection between horizontal and vertical lines on the screen. So does this intersection have a physical shape and size and what happens when an image or video of say 1600X1200 is played on screen having resolution of 800X600 or vice versa. I have searched a...
  43. V

    Helmholtz 2D PDE around general shape (eg a figure 8)

    Hello physics enthusiasts! I was looking for resources, and stumbled upon these awesome forums. I am looking for how to solve the helmholtz equation / wave equation on a figure 8 type shape. I wanted to find the resonant frequencies of a classical guitar. Would this work? I am considering...
  44. L

    What Is the Shape and Expansion of the Universe?

    Hello, I'm working on an assignment where I explain some things about the universe. This is what I'm writing about and also in the order in which I'm writing about it: Part I The Shape of the Universe Matter The static model of the universe A universe which...
  45. D

    Gas pressure and container shape.

    I've been thinking about the ideal gas law lately and there is something I don't understand. Say you have 2 containers filled with an ideal gas. Both containers contain the same moles of gas, the same temperature of gas, and both containers have the same volume. Therefore, according to the ideal...
  46. E

    Shape, structure, and nature of the universe - questions/theories

    Hey guys, newbie here! I stumbled upon your forum while searching for an explanation i was looking for in regards to some theories/questions i have about the shape, structure, and nature of the universe... so here goes! I have some fundamental issues/differences in opinion regarding the...
  47. M

    Is a Deltoid Wing the Same as a Kite Shape?

    As title... I am wondering is deltoid same as 'kite shape'? Thanks in advance...
  48. M

    Shape of titration curve in vol (NaOH) vs vol (HCl)

    In an experiment titration. The NaOH was added drop wise into HCl in a conical flask. The number of drops of NaOH was recorded against the varied volume of HCl in the flask. A graph was to be plotted of number of drops of NaOH on the y-aixs to Volume of HCl on the x-axis. What would the...
  49. S

    Why Are Planetary Orbits Elliptical?

    Why are the orbits of planets revolving around a body(say the sun) elliptical rather than circular or any other shape? Please show the answer mathematically.
  50. D

    Changing shape of calabi-yau manifolds: flop transitions

    Hi all, I was reading a paper written by Brian Greene sometime ago on flop transitions where one can essentially change the topology of the manifold but the four-dimensional physics that applied to the older manifold still holds. From that I am trying to extrapolate the following: Is it...
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