Shape Definition and 613 Threads

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...

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...

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...

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?

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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?

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...

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...

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...

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...

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...

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

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

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...

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...

[FONT=Georgia] [FONT=Georgia]Read full paper by click here. [FONT=Georgia]

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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

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...

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...

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...

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

Is this so? I cannot think of a counter-example and it is too general a statement to prove.

Model aircraft display a wide range of aerofoil shapes, and many of these models fly despite the shape of the cross section of the wing. Models with flat wings, cambered wings, thick wings, thin wings - all of these fly succesfully. What is the function of aerofoil shape on free flight...

Hi! In the description of the Stern-Gerlach experiment made in Sakurai's book the magnet is shaped to have a pointed edge. What is that for?

What is the shape of an "isodistance" volume from the point of view of an observer traveling at relativistic speeds? (EDIT: ... compared to that of an outside observer) If it is not spherical, how do the distorted (?) distances of all mass objects surrounding the observer affect the observer's...

In my book they explained that a trigonal planar shape is not good because of the 3 lone pair bond-pair repulsions between the unhybridized p orbitals and the 3 trigonal planar bonds. So it would be more favourable to have the orbitals hybridized into a tetrahedral shape to minimize those 90...

Homework Statement An inextensible string of length ##\ell##, whose mass per unit length is ##\rho## is hung between two points at the same height a distance ##d## apart (##d < \ell)##. Using the Euler-Lagrange equations and the first integrals, find the shape of the string when it is in...

Hi all, It is well know that, rectangular or quadrilateral element gives better result over triangular meshes in finite element method. I know, Rectangular meshes has more discretization error, but my question is that, if i refine mesh up to 4 to 6 pixel width of screen, where i am wrong?