Dimensions Definition and 1000 Threads

Homework Statement As an example of the manipulation of an electron beam, consider an electron traveling away from the origin along the x-axis in the xy plane with initial velocity v = vi. As it passes through the region x = 0 to x = d, the electron experiences acceleration a = ax + ay, where...

I need help in seven exercises of physics, I just don't know what do... I'd like you to do one or more exercises with it's process so that I can analyze somehow the process and learn how do to it, I have an exam tomorrow and I have to study.. here are the problems: 1) An artillery shell is...

:cool: I'm doing my doctorate dissertation on the determination of molecular dimensions. I alredy know avagadro's constant and can understand the science of it, but the math is very complex and difficult to understand.:confused: I also need to know the different experiments that can be used...

Im not sure if this is the proper area for this but when they say that there might be other dimensions that we don't no about are they referring to more than xyz? i mean how could something have another dimension, it seems weird to think about. Just looking for someone who has some insight on...

Homework Statement what are dimensions of [V]volume and [v] speed expressed as powers of length, mass, time. Homework Equations The Attempt at a Solution i thought of speed as miles per hour...but didnt come out right.

Homework Statement A soccer player kicks the ball toward a goal that is 16.8 m in front of him. The ball leaves his foot at a speed of 16.0 m/s and an angle of 28.0 degrees above the ground. Find the speed of the ball when the goalie catches it in front of the net. Homework Equations x =...

What is the true definition of our universe in terms of spatial dimensions? Should the definition of universe include higher spatial dimensions? Is the expansion of our universe causing gravity; if our universe wasn't expanding, would we have the natural phenomenon of gravity? Is the...

Question and Data What is the initial velocity of an object that rolls off a table and hits the floor below? Lab produced the following data: Table height: 86 cm Distance of object from table when it hits floor: 23 cm Relevant equations Instantaneous Speed: Vf = Vo + at [I think this is the...

Homework Statement A playground is on the flat roof of a city school, 6.00m above the street below. The vertical wall of the building is 7.00 m high forming a 1m high railing around the playground. A ball has fallen to the street below and a passerby returns it by launching it at an angle of 53...

My question seems rather simple, but I could't have the right answer. Hope you can help me about it. Thanks! Determine a convertion factor that, upon multiplication, changes an acceleration in miles per hour times second (mi/h*s) to meter per second squared (m/s^2).

A golfer imparts a speed of 30.3 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) how much time does the ball spend in the air? (b) What is the longest "hole in one" that the golfer can make, if the ball...

Homework Statement A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.00m/2 at an angle if 20 degrees below the horizontal. It strikes the ground 3s later. (a) How far horizontally from the base of the building does the ball strike the...

Homework Statement here's a picture of what the case is : http://img67.imageshack.us/img67/6425/imagevn8.png" if I drop a ball with the initial velocity is v at h. How do I find R here in terms of h? Homework Equations The Attempt at a Solution

Something seems a little weird to me: What are the dimensions of a generating functional, Z[j] -- say for real scalar field theory? Z[j]=\int\mathcal{D}\phi\,\exp\, i\!\int d^4x\left(\frac{1}{2}\partial_\mu\phi\partial^\mu\phi-\frac{1}{2}m^2\phi^2+j\phi\right) Also, what about mass dimensions...

I am trying to teach myself AS maths. This is from Introducing mechanics a txt book by Jefferson and Beadsworth. exercise 2C question 1 part vi) Question given vector b=6i-3j-2k; |b| is established as = 7 by calculation Question Calculate the angles between b and positive x-, y- and z-...

What are the "Extra Dimensions" in the LHC experiment? First of all, I'd like you people to know that I'm a 10th grader. So yes, silly questions may follow. As the topic says, I want to have an idea of what the 'extra dimensions', that might possibly be discovered in the LHC experiment...

what are the dimensions of angles?

Homework Statement A particle leaves the origin with an initial velocity v = 3.92i , in m/s. It experiences a constant acceleration a = -1.00i -0.80j , in m/s2. What is the velocity of the particle when it reaches its maximum x coordinate? i-component of velocity? j-component of the...

Problem in equations of kinematics in two dimensions..please help Hi, I'm a first year physics student and am studying equations of kinematics in two dimensions and projectile motion. I was given the following question as homework to prep for my first exam this Wednesday. I'm pretty solid on...

Homework Statement Let A = (a_1, . . . , a_{2008}) \in \Re^{2008}, where a_i = \frac{1}{2^{i}} for each i = 1, . . . , 2008. Find the distance from the point A to the origin. Please express your answer in the form \sqrt{\frac{a}{b}} where a, b are integers. Homework Equations Extended...

Given F = (-20i + 50j = 10k) 1. The component of the foce projected along the pole AO. 2. The magnitude of the projected component of the F along the pole AO. I have no idea where to begin, I think I need to find the angles but I'm not sure how in three dimensions. (please excuse...

Well i do understand about the 8 fundamental dimensions in physics, but i cannot understand what makes only the length, mass and time to commute with one another to produce derived units like force or acceleration. Why cannot we have a unit something like K^2 or sqrt(candella)?

Just wondering. All this stuff of the brane world, where spacetime is a 3-brane inside a 10 dim world... is not the same than telling that we want to use non compact extra dimensions?

Homework Statement Find the dimensions of a rectangular box with the largest volume with surface area 64cm^2. Homework Equations area of a rectangular prism 2xy+2yz+2xz The Attempt at a Solution took 2xy+2yz+2xz=64 rearranging for z: z=(xy-32)/(y+x) partial derivative of z...

1) Which of the equations below is dimension- ally correct? a. y = (2 m) cos(k x), k = 2 m-1 b. v = v0 + a x my work for: a) cos(kx) = 2ym-1 So this would lead to k = (1/x)cos-1(2ym-1) But i don't know whether the COSINE operation on RHS changes m-1 to any other unit or not. So...

Hello folks, this is going to be a bit longish, but please bear with me, I'm going nuts over this. For a term paper I am working through a paper on higher dimensional spacetimes by Andrew, Bolen and Middleton. You can http://arxiv.org/abs/0708.0373" . My problem/confusion is in...

hi, as the topic title suggests, is that possible? i was reading an article on string theory and i vaguely recall that humans live in a 3d world with an additional dimension of time. if we can live in such a space time dimension, would it be possible that there are organisms/beings living...

Hello there, I'm currently trying to get my head around General Relativity for a term paper; the twist is that I'm dealing with an arbitrary amount of dimensions, that is 4+d, where d is unspecified. Now the maple tensor package does calculation with some fixed amount of dimensions just...

This may be a stupid question, but I have been curious about it for awhile. Before string theory, extra dimensions seem not to be taken seriously. But if gravity warps space doesn't it need another dimension to warp into? I saw Brian Green on TV and I thought he suggested that you don't, but he...

This is a question in my textbook: "The hyperplanes H1 and H2 have dimensions p and q, respectively. What is the smallest dimension which the hyperplane H3 must have in order to be sure to contain both H1 and H2?" I reasoned it out like this. A basis for H1 would be x1 + x2 +...+ xp...

I bought a book on susy and there is a chapter on spinors in d-dimensions. Now, maybe I am extremely dumb but I just can't understand the first few lines! EDIT: I was being very dumb except that I think there is a typo...See below... BEGINNING OF QUOTE Consider a d-dimensional...

As far as I remember, I heard from someone that the matrix \gamma^5=i\gamma^0\gamma^1\gamma^2\gamma^3 also known as the chirality operator in 3+1 dimension is not defined in odd dimensions. I do not understand why that should be the case. Suppose I am in the 4+1 dimension and I choose one...

Is there any fundamental difference between the 3 dimensions of space that we experience. Such as the difference that we intuitively feel between the time and space dimensions

Homework Statement If A is a 6x6 matrix with characteristic polynomial: x^2(x-1)(x-2)^3 what are the possible dimensions of the eigenspaces? The Attempt at a Solution The solution given is that, for each each eigenspace, the smallest possible dimension is 1 and the largest is the...

How does one calculate the number of components a Dirac spinor in arbitrary dimensions? As far as I understand, the textbooks treat the four spacetime dimensions and here the spinor has four components because the gamma matrices must be 4x4 in nature to satisfy the required algebra. Now suppose...

I read somewhere that string theory could be disproved if it is found out that the universe expanded at a certain speed as this would cause the extra dimensions to unravel and therefore mean that string theory could not describe our universe. I do not understand why the extra dimensions would...

I don't know anything about GTR, nor do I know anything about differential geometry. But I have one maybe stupid question: As far as I know space-time in general relativity is represented by a pseudo-riemannian manifold. And according to Whitney's (or Nash's? - don't know who is in charge here)...

Homework Statement Does the wave function have a dimension? If it does, what are the dimensions for 1D and 2D box problems?Can you generalise this to n dimensions? Homework Equations The Attempt at a Solution Yes, it does have dimensions. For 1D box it's [tex] m^{-2} [tex]...

My main question is if the Maxwell equations have been generalized to include extra dimensions in an generally accepted form, or is it still under investigation? I've already read http://arxiv.org/pdf/hep-ph/0609260v4 but I didn't quite like the add-hoc assertion We assert that in all...

Recall that for a function f:A\subset \mathbb{R}^n\rightarrow \mathbb{R}^m, the derivative of f at x is defined as the linear map L:R^n-->R^m such that ||f(x+h)-f(x)-L(h)||=o(||h||) if such a linear map exists. We can show that for certain geometries of the set A, when the derivative exists...

Hi, I have a Mechanics vector problem here split in two parts. First to solve the magnitude of the resultant vector and then to give the bearing at which it's acting at. Worked out most of it, but the last answer to the question isn't the same as mine. Kind of difficult to explain the question...

I was told by my old physics teacher that there is proof (mathematically) for around 14 dimensions or something crazy like that. I think he said it was in relation to string theory and the amount of dimensions they need to oscillate as we think but seriously, we have x,y,z planes and time...

SU(3) needs to act on a minumum of 4 compact dimensions. SU(2) needs a minimum of 2 dimensions U(1) needs a minumum of 1 dimension Thus SU(3)xSU(2)xU(1) needs 7 extra dimensions. Because of this, string theoretists do not use the extra dimensions to generate the gauge groups, and they use...

Homework Statement Consider a Rocket in space, far removed from external gravitational influences, and suppose the engine starts up. As long as the engines are running, its instantaneous velocity v is a function of its mass. V is given by: V = A + B log(D/m) A, B, D are physical...

I have been reading about dimensions, and I understand that: A dot has no dimensions A line has 1 dimension A square has 2 dimensions A cube has 3 dimensions A tesseract has 4 dimensions And time is another dimension just like those In theory we can think of lines and squares, but we...

What do they mean by a dimension that's curled up? I'm having a hard time with this notion. What would such a dimension be like?

This has been bugging me for a while, but feel to tell me if it's a nonsensical or silly question.. Suppose there were 4 spatial dimensions instead of 3. How would we go about constructing the Pauli matrices? Assuming each matrix still only has 2 eigenvectors, we require 4, 2x2 mutually...

What will be the dimensions of temperature in a particular second, say the 10th?

Has anyone ever analysed Einstein's equations in 1+1 spactime dimensions? It seems to me like this would provide a convenient toy model for teaching or learning general relativity. For one thing the spacetime curvature can be visualized as curvature of a 2-dimensional surface.

Homework Statement 1. What is the meaning of Planck’s units? Hint: Compare the strength of the 4 fundamental forces. 2. Calculate the Planck’s dimensions as a function of the SI units. 3. What are the dimensions of the human being in terms of Planck dimensions?Homework Equations Plancks's...