Dimensions Definition and 1000 Threads

Homework Statement A box has a length that is 13cm longer than its width, and the volume of the box is 60cm^3. Determine the dimensions of the box. Homework Equations V = lwh l = 13cm > w h = ? The Attempt at a Solution Since V = lwh, 60cm^3 = lwh and, l = 13cm > w w...

Sorry. I know I must sound like a hick. Time is ... the 4th dimension of our conventional reference? If so, are one or more of the other dimensions posited by String Theory considered possibly to be an additional time dimension(s)?

Consider a system where the three fundamentally important quantities are the speed of light C with dimensions (L)/(T), Planck's constant H with dimensions (M)(L)^2/(T), and the mass of the proton M sub p with dimension (M). a) What combination of ratios and/or products of C, H, and M sub p will...

Hi math fans, Only me, I have been asked to do the seemingly impossible and find away of distinguishing four signals from three dimensional space. Any ideas guys - left me stumped. Thanks for thinking about it anyway Cheers Duane

According to string theory there are an extra 7 spatial dimensions curled up at every point in space. They are so small(Planck length) that nothing can move through them and are completely undetectable. My question is this: Does string theory allow for these dimensions to uncurl and become...

Litterature on "small" or "compact" dimensions? Hi! I'm reading some Kaluza-Klein theory which is an extension of normal 4D GR to a 5D spacetime in which the fifth dimension is a "small" or "compact" extra spatial dimension. I've found loads of literature on the differential geometry of...

Homework Statement A bird flies from Lesser Slave Lake in northern Alberta to Dore Lake in northern Saskatchewan. The birds displacement is 800.0 km [E 7.5deg S]. The bird then flies from Dore Lake to Big Quill Lake, Saskatchewan. This displacement is 400.0 km [E 51deg S]. The total time of...

Find a two unit vectors that make the angle \pi/3 with the vector \vec{v} = \vec{i} + 2\vec{j} + 3\vec{k}. "That isn't asking much since there are apparently infinite such vectors" - Prof. I get as far as to say that \pi/3 = arccos( 1/2 ) and that \frac{v \bullet w}{|v||w|} = 1/2 but from...

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Homework Statement During baseball practice, you go up into the bleachers to retrieve a ball. You throw the ball back into the playing field at an angle of 42° above the horizontal, giving it an initial velocity of 15 m/s. If the ball is 5.3 m above the level of the playing field when you...

On the page 17 of this article by Max Tegmark http://arxiv.org/pdf/gr-qc/9704009v2.pdf, in figure 7, it has been argued that why spatial dimensions other than 3, is not possible for our universe. But in string theory, people are talking about 10, 11 or 26 spatial dimensions (even if these...

Homework Statement Twelve equal rectangular ceiling panels are placed in a four long by three wide grid. Each panel is 150mm longer than it is wide. Between the panels runs an edge/middle strip which totals 40.0m in total length. (This runs round the whole perimeter and between each panel)...

Local Electrodynamics in higher dimensions?? So I am an unexperienced undergrad but the other day I had a few thoughts which are most likely crazy. I'm just wondering why they don't work. And whether the questions I'm asking are answered elsewhere. So I've heard: (i) Maxwell's...

Does the math in string theory tell us anything about the size of any of the extra dimensions?

Let me try to explain. If I take a reel of movie film, I can unwrap it see different frames simultaneously. How ever if I were "trapped" in the movie I could only experience one frame at a time. Now this example is not a direct proposition I am making. It''s just to imagine a higher...

I am unsure how to proceed with this problem because it is asking for the final velocity of one of the two objects given the initial velocities. This is an inelastic collision not a completely inelastic collision, which means the two objects do not stick together. The book makes a distinction...

In an experiment, one of the forces exerted on a proton is F = −αx^2i , where α = 14.4 N/m2. (a) How much work does F do when the proton moves along the straight-line path from the point (0.10 m, 0) to the point (0.10 m, 0.5 m)? (b) Along the straight-line path from the point (0.09 m, 0) to...

hello, The Weyl tensor is: http://ars.els-cdn.com/content/image/1-s2.0-S0550321305002828-si53.gif In 2 dimensions , the Riemann tensor is (see MTW ex 14.2): Rabcd = K( gacgbd - gadgbc ) [R] Now the Weyl tensor must vanish in 2 dimensions. However, working with the g g = [-1 0 0...

So I watching this video on dimensions.. and I have a few questions: 1. How many dimensions are there? (that are proven with hard evidence) 2. The video was talking about 4-Dimensions - is it pretty much the same thing as 3-Dimension + time?

Are "small" extra space-time dimensions represented correctly? This is my first post, I searched briefly but I apologize if this is a commonly covered topic! The following is written in the spirit of the "aether" -- that, being an overcomplication with no evidence. One of my biggest...

Hello I have heard that Greens, Stokes and the Divergence theorem is the equivalent of the fundamental theorem in multiple dimensions. But is there some way to show the result under: if F(x,y) = \int_{-\infty}^x\int_{-\infty}^yf(x^{*},y^{*})dx^{*}dy^{*} this implies that...

Basically, I'm writing a story that involves beings of 5 spatial dimensions visiting Earth. And when I say "writing" I mean "putting thoughts down on paper as they come to me" or almost that, i.e. not much thought has gone into world-building. Mostly 5-dimensionality manifests in crazy...

Hi Please can someone help me calculate the minimal thickness and width that will resist bending in each of the aluminium beams that are fixed on one end and support a 0.0013734 Newton load on the other. The axis passes through the center of the octagonal shape and goes into the page...

Homework Statement Hi, I am trying to find the general formula of a circle in 3D Let's consider a sphere centred at (x1,0,0),with radius x1 It's equation is (x-x1)^2 + y^2 + z^2 = (x1)^2 If there is a plane x = x1 intersects with the sphere A equation of a circle is formed,which is y^2 +...

If two units have the same dimensions are they always inequivalent? I was thinking, would doing dimensional analysis on units prove they are equivalent or could they have the same units but not be equivalent.

ok so I am not sure how else to do this problem, my answers look similar to those in the book. where they have β=52.5 \alpha=121 \gamma=53.1, I feel like the book is wrong because i don't see any other way to solve this problem...

Hi all, Had a doubt regarding Laplace's equation. In many textbooks, the general solution to the two dimensional Laplace's equation is mentioned as: \Phi(\rho,\phi) = A_{0} + B_{0}ln(\rho) + \sum_{n=1}^{\infty}\rho^n(A_ncos(n\phi) + B_n sin(n\phi)) + \sum_{n=1}^{\infty}\rho^{-n}(C_n cos(n\phi)...

pleese don't critical on my little knowledge of this. a few of us have bull sessions sometimes and my cousin points front side up and says we live in 3 dimencions but the whole universe is 4 dimencions. this other guy always says my cousin is full of bull and einstine just used them for...

I just noticed that torque has dimensions of energy! What does that mean?

Lagrange Multiplier----to find out the dimensions when metal used min. Homework Statement I have a rectangular tank with a capacity of 1.0m^3. The tank is closed and the cover is made of metal half as thick as the sides and base. Find the dimensions of the tank for the total amount of metal...

I am confuse about the dimension of an operator? Why we need an operator of Dim six or greater for new physics?

If the universe follows a 3-torus or finite unbounded shape, or we are situated on the surface of a 4D sphere, then the 'centre' if the universe will exist. If one could locate the position of this origin in 4D space, and remain stationary with respect to it, then would that object be at...

I'm having a hard time grasping the concept of a vector geometrically. A vector in $$ℝ^2$$ is a line going in the direction specified from the terms. A vector in $$ℝ^3$$ is similary just a line going in the direction specified by the terms. But what exactly is a vector in $$ℝ^n$$ where n is...

Hello, I'm Nate, and I'm looking to build a compressed-air engine. I'm using a pneumatic cylinder with a 3" bore and a 12" stroke. That was simple enough to find. What hasn't been simple to find is a manual valve large enough to actuate it. I've found small 5-way valves on ebay and amazon, but...

Homework Statement Knowing that the stress and strain for an isotropic media can be related with the following expressions: \sigma_{xx} = (\lambda + 2\mu)\varepsilon_{xx} + \lambda\varepsilon_{yy} + \lambda\varepsilon_{zz} \sigma_{yy} = \lambda\varepsilon_{xx} + (\lambda +...

Homework Statement The following enclosure is built using 280 m of fencing. If the enclosure has a total area of 2800 m2, what are the dimensions to the nearest tenth? Homework Equations x = \frac{-b ± \sqrt{b^{2}-4ac}}{2a} The Attempt at a Solution Please note that the 3/2w and 5/2w...

A lot of below might be a question of semantics however it helps to understand better, I am a novice: 1. What's the difference between a field and a dimension? A field is present at all points in time and space, ...so is a dimension. why don't we call/label a field as a dimension? 2. or...

Right, Hello, I am new to this, and do not have much understanding, but can someone here help explain the Dimension Models and String theory to me?

Will someone please explain to me how a theory, such as a quantum field theory, be expressed in more than three dimensions? Is this referring to the spatial dimensions we live in now, or what? And how does someone even begin to ponder these multiple dimensions?

Hello everyone, I’d like to find the following range equalities: Considering the following: A=B+C \\ A=B.C^T \\ A=[ B^T C^T ]^T I would like to find the function f for each equality above. .\\ dim( R(A) ) = f( R(B) , R(C) )\\ Considere that all matrices have compatible...

Homework Statement Find the work done by a force acting in the direction 2i - 5j + k in moving a particle from (3, 3, 1) to (1, 2, 4). Homework Equations The Attempt at a Solution I just found the displacement vector (2,1,-3) and did the dot product with the force vector...

Apriori, I don't see why there should be 10,11 or 12 dimensions? Can't we have indefinitely number of dimensions? Or such an option isn't viable cause we can't test it empirically (not that the hypothesis of less dimensions is testable either, besides the 3+1 we know already).

[FONT=Georgia]Look at this page and the Proof part, Fermat's theorem (stationary points) - Wikipedia, the free encyclopedia [FONT=Georgia]How to change the proof 2 into a proof of higher dimensions or can you give a proof of Fermat's theorem of higher dimensions?

So I just got out of my linear algebra midterm, and this question is confusing the hell out of me. Basically, it's a subspace of R^4, such that the coordinates satisfy the following qualifications: (a, b - a, b, 2(b - a)) So basically, a and b can range over the xz plane, and y and w sort...

Homework Statement Given v1, v2 ... vk and v, let U = span {v1, v2 ... vk} and W = span {v1, v2 ... vk, v}. Show that either dim W = dim U or dim W = 1 + dim U. The Attempt at a Solution I'm not really sure where to start. If I knew that {v1, v2 ... vk} was linearly independent, then it would...

Suppose we have a 2d problem (for instance a 2d box). You look for separable solutions in x and y. But it seems to me that the solutions are in a way determined by how we choose the separation constant. Do we know anything a priori that tells us if the separation constant should be negative or...

What is the nature of sound in each dimension e.d 1D, 2D, etc and how can one be differentiated from the other. I do not seek formulas just a straight forward explanation.

Dear experts, I'm not familiar with crystal structure theory. I'm seek expertise to figure out space groups in 2 dimensions Bravais lattice of the attached structures. In the figure, red and greens dots represent different atoms. I'll greatly appreciate your help. Struture 1...

I would like to know what effect does tire width and tire diameter has on performance or overall efficiency of a vehicle.

Homework Statement Three cables are used to tie the balloon shown in the figure. Determine the vertical component of the force P exerted over the balloon at point A, if the tension on cable AB is 259 N. http://img521.imageshack.us/img521/9687/physicsballoonproblem.png (Sorry for the figure...