Shapes Definition and 157 Threads

Consider the two shapes circle and circle with a line attached it. (Figure is attached) Are they topologically same?. As far as I know if we bend, stretch a shape and attain another shape both are topologically same. I feel that circle can be stretched in some way and can be made to a circle...

If I were to build a solenoid for the sake of making an electromagnet with a core shaped like the one below, would it create the desired effect? CRUDE! :-p Cross-sectional view of my idea. What I'm asking is, would the inner edges of that gap (the sides closest to the center) be one...

I'm working on a project to replace hollow structures, (pipe, sq. tube, ect...) with open structures, (channels, angle iron, ect...). It's been a while and I think that all I would have to do is compair the moment of inertia for each of these shapes and make sure that they match or are larger...

what is exact reason behind choosing basic primitive shapes for elements in FEA? Why it can't be hexagonal, pentagonal, octagonal, etc. in both cases 2D and 3D... Thanks in advance...

im having a little trouble trying to picture an atom in my head with accurate electron cloud designee and shape can someone give me some pictures or a site that might help. every picture i ever see of an atom is with the electron orbital in curricular shapes but i know there is a wide eray of...

Homework Statement (1) Which of the following clusters of orbitals would form the shape shown here http://session.masteringchemistry.com/problemAsset/1076900/19/1076900b.jpg and would also be possible within the valence shell of an atom? a.) one d orbital b.) five d orbitals c.) five sp^3...

Reviewing basics of electrical theory [right hand rule; Faraday's law; etc.]. Come to surprising conclusion: If a number of wires are arranged like the spokes of an old fashioned wagon wheel and current flows through these wires towards the center, a magnetic field is generated which is the...

I came across these on the arxiv blog, thought it was kind of interesting, although utterly disconnected from reality: http://arxiv.org/abs/0904.4311 http://arxiv.org/abs/1003.2411

I am writing a science fiction story about a strange universe. I have a few questions which fall in the same general category. 1) What sort of gravity would allow a planet to maintain the shape of a dodecahedron? 2) If there exists a planet, where the physical laws are the same as in this...

Hey all, I'm sure this is simple, but I can't seem to find the answer in the Maple help section. When drawing 3D shapes, I want to be able to up the number of dots used to constitute the image, thus increase the resolution of the object. My spheres are showing up a bit boxy...

Hi a bit random this question, but I'm trying to divide a sphere into many equal shapes (round-ness isn't important). So far I've come up with a dodecahedron, 12 pentagons. This isn't enough of a division for my needs. Can anyone give me the names of geometric shapes that have more divisions...

As the title suggests, i have to make cuts in a piece of plastic about the same dimensions as a credit card. the shapes themselves are fairly simple, mostly triangles, with 4 quarter circles on the corners. the device i have in mind would be something which i guess looks like a mechanical...

Greetings, The other day while working on my car I began thinking about solenoids and how they work, but I think I may have confused myself. It's been a while since I've studied magnetism, but I remember that the current through a wire loop, and thus a solenoid as well, is dependent on the...

I'm creating a C++ 2D program to practice my 2D skills. I'm almost done with everything but I'm stuck on this crap. Is there any formula on how to rotate a shape? Example: I have a line P1(-1,-1) P2(1,1) If I rotate it by 45 degrees, I'll get a P1(1,-1) P2(-1,1). By the way, it should...

#ifndef SHAPE_H #define SHAPE_H #include <string.h> using std::string; using namespace std; class Shape { public: Shape(const string &color); //constructor ~Shape(); string getColor()const; //returns objects color value virtual double area()const = 0;// a const pure...

I think I'm right when I say that the centroid of a 2D shape is found by the intersection of the lines that separate that shape into two shapes of equal areas. Is that correct? I don't want to (for now) think about it in terms of moments and integrals, because frankly, it's a little confusing...

When looking at the design of the both the U.S. Saturn V rocket, and the Soviet N1 rocket, there is an obvious design difference between the basic overall rocket body shape. The Saturn V shows several conical regions, with a straight body design throughout. The N1 shows more of a...

i was wondering what are some more popular ways to graph or get an idea of how a shape of an function would turn out to. the way I've learned it is to set certain variable to zero to get a certain plane. for example if i wanted the the xy plane of a function such as x^2+y^2-z^2 = 1 i would need...

Good morning, First of all I would like to express my congratulations for the forum ! It is very nice. I am new colleague in physics teaching and i would like to ask how can sb draw beautiful shapes like these : wikipremed.com/interdisciplinary_course.php?code=010102 Does any special software...

Hi all, Can anyone let me how the following puzzle can be solved : draw a square. divide it into four identical squares. remove the bottom left hand square. now divide the resulting shape into four identical shapes Thanks, Suppie

Ok I am try to understand how to find the moment of inertia of different shapes by using direct integration. In a lot of the solutions I see they always have this one thing that I don't understand. Example: Determine by direct integration the moment of inertia of the shaded area with respect...

The question I am dealing with has to do with the volume contained by two intersecting shapes I have created this integral and can't find a reasonable way of solving it. What is the best approach to solve this: \int_{r=0}^{\pi/2}\int_{u=0}^{2\cos\theta} \sqrt{9-r^2} * r drdu=

How would I find the resistance of said circle Outer Radius 4a Inner Radius a Thickness .15 mm

What makes us able to change the expression of some genes and unable to change the expression of other genes?

We know that orientations of electron orbit are discrete , what exactly do you mean by discreteness ,& also is there any particular shape of orbits like an ellipse ?

Hi all, I wanted to know if anyone had any advise on how to transform a 2D geometric shape into a 3D one. I have some 2D shape which is given by the equation f(x,y) = const. = k. I wish to rotate this 2D shape into the 3rd dimension by an angle theta and then write down what the 3D function...

I am looking some help on applying the well known formula of the electrostatic force between two parallel capacitor plates on charged surfaces which have non usual shapes. My approach is to break apart the total surface into segments with common shapes and calculating the force between each two...

Homework Statement Give the formula of a fluoride molecule that: is octahedral in shape is trigonal bypyramidal in shape is T-shaped ...etc The Attempt at a Solution Ok, I'm not really actually looking for an answer, because I already know the answers are SF6, PF5, and ClF3. And I have...

I've been studying absolute uncertainties and do not understand any of it. If someone can explain it will really help. Especially with uncertainties including diameters and area.

Please can someone tell me whether anyone has managed to classify all possible 3-D shapes into a finite and usefully small number of categories? At school level, most shapes seem to be some part, or combination, of:

Air or Water: I'm looking for information on fan and propeller shapes (ducted and non-ducted) which might lead to more quiet if not more efficient shapes. Noise is lost energy just as heat is lost energy in a mechanical system, right? I have a thread which contains many bits of...

how can i solve this problem!?? thx

Hi, I have nothing to do this summer so I figured I would like to model the heat transfer for different shapes and fluids and compare with experimental values.. :) Anyway I searched on google and found nothing. What are the main problems? For example is it acceptable to assume that the...

We have this final project for my math class and I was thinking of using geometeric series to get different shapes. I found this great website http://www.ugrad.math.ubc.ca/coursedoc/math101/notes/series/serapp.html but our teacher has already used it as an example. Do you know any other easy...

1. Determine the shapes of Br2 (2 Bromine atoms) and HBr. Which is more polar and why? 2. No equations. 3. Okay, I know that Br2 and HBr molecule shapes are linear (I know how to draw them) but I do not get how to find which one is more polar. :confused:

this may seem quite stupid to many of you but i was wondering how it is possible to draw 4D objects. I have seen pictures of 4D objects such as the hyper-cube etc, but they are drawn in three dimensions. The picture of a hyper cube that i looked at seemed to me to just look like a cube with a...

I don't think the problems I'm going to post are very difficult, but I'm totally clueless regarding chemistry, so they're pretty difficult for me ^^;; I also have a lot of questions to ask, so I hope you don't mind my sticking them all into one topic. I'm looking forward to your help. You don't...

Hello, (edit should be regular polygons in title) I have been thinking a lot recently about 3D shapes formed by 2D regular polygons. I was asking myself if there would be any way to calculate the minimium number of regular polygons to form a complete 3D shape. It is fairly easy with an...

How can I tell how many four sided shapes are here? Counting seems so... not what a smart person would do. http://www.mensa.org/images/fourside.gif

I don't even know how to phrase this, let alone which forum it should go in. I'm trying to design a valve, like in a blood vessel. I want to ensure that the design "works" i.e. the shape of the valve will be determined by the volume of fluid moving through it. So, what shape will it take over...

This is an my topic for my essay. I'd like it if people can post up some theories to this topic. I am investigating why is it that commercial planes have a round nose whereas most fighter planes have sharp noses (Like the beaks of birds) and why F1 cars cars have a conical nose cone instead of a...

I am having a lot of trouble understanding the following: 1) How do I determine if the shape is a trogonal planar? Is it because it would have more bonds than the tetrahedral? 2)Is figuring the polarity of a molecule only based on the electronegativity? Please help! I have a big test...

A gravity graph is a kind of art "tool" that let's you draw nice geometric shapes. It has a board the size of a piece of paper that is weighted in the middle, each of the corners is connected to a piece of string and the strings are tied to a small rectangle (paralell to the board) about 1.5...

Here is the question An upright square pulse and an inverted triangular pulse were directed toward each other on a spring, as shown in the illustration. Sketch the appearance of the spring at the instant the two pulses met and completely overlapped. What principle did you use in...

shapes of potentials! Hi all.. 1)we have,for example,rectangular, square well, well type etc potentials. How is the shape of a potential is determined? What is the shape of the nucleus potential? 2)I am unable to get the physical importence of the wave vector 'K' and K-space in band...

how is radiation view factor calculated especially for the following cases 1-between a flat surface and a sphere between two flat surfaces at 90 between two surfaces facing each other between two spheres

Please, can someone answer my question? I know the shape of sp hybrid orbital, but want to know about the others ( sp2,sp3,dsp2,dsp3,d2sp3,d3sp3 ). And are there any other type of molecular orbitals?

What does everyone know about these multidimensional knots?

http://img62.imageshack.us/my.php?image=geometry9cn.png

perhaps an elementary question for such a bunch of wizards, but here goes - why do clouds form into definite cohesive shapes? since the static charges of the mixed vapor molecules are all negative (to the point where they eventually will build up enormous negative density and discharge as...