2d Definition and 1000 Threads

How much more than is to learn when you go from 2D to 3D? I'm curious to know whether all these problems I solve in 2D are less helpful for when we move to 3D, where there are more elements?

Confusion with 2D DFT Hello everyone, I'm trying to figure out why the third transform in the picture I attach here is different to the other ones, why it's 'distorted'. I know that it's related with the fact that if you copy the image in a grid the resulting image has discontinuous lines...

Dear all, I having a trouble in defining 2D and 3D stress . As I know Maximum principal stress in 2D and 3D cases is totally different. In which condition we should apply 2D stress formula and when we need to use 3D stress formula?

Hi, i have an assignment to make a code for a connect 4 game,using module and subroutines, but as of now I am stuck, and do not now where to go. Any help would be great. here's what I have so far. I'm stuck on how to declare where the X's and O's will show up and how to determine when 4 in a row...

1. The problem statement I'd like to use Matlab to help me model and solve a simple 2D steady state heat conduction problem: A square section duct is buried in the Earth some distance below the surface. This duct is at a steady temperature of 60 degrees C. I need to use the central divided...

Homework Statement You are on the top of a 100m high (approximately 30 story) building. You just finished building a brick grill so the tenants of the building can have barbecues. You have one brick left and do not want have to lug it back off the roof. Luckily, you see a garbage truck with...

2D Momentum Problem with little info for Object [B] Homework Statement A 0.150kg billiard ball [A] is rolling toward a stationary billiard ball [B] at 10.0m/s. After the collision, ball [A] rolls off at 7.7m/s at an angle of 40.0 degrees clockwise from its original direction. What is the...

Hi, After considerable simplification in a problem I'm working on, I end up with the following partial differential equation: \partial_{\eta}\left(\frac{\sinh\eta}{\Delta}\partial_{\eta}g\right) + \partial_{\theta}\left(\frac{\sinh\eta}{\Delta}\partial_{\theta}g\right) + c^2\left[\frac{E_{p}...

program pr2 implicit none integer:: i,j real, dimension(21,80) :: istat open(7,file='sens.dat',status='old',action='read') read(7,*)((istat(i,j),i=1,21),j=1,80) write(*,*)istat end Where is the problem?Input file has 1680 values.But I get...

Homework Statement : A cart 'C' mass of 2 tonnes is launched at 10m/s towards Cart 'B' which is 3 tonnes and moving at 12.5m/s. The angle between their paths of motion is 90 degrees. When the 2 carts collide, they remain stuck together. what is the velocity of the stuck together cart 'CB'...

I am trying to figure out how you would write out a matrix for the solution to an equation such as the following: \alpha x^{rr}-(2\alpha+2\gamma) x^r+(\alpha+\gamma) x^i+(\beta+\gamma) x^{br}-\beta z^r -(\beta+2\eta) z^b+(\beta+\eta) z^i +\eta z^{bb}=0 where alpha, beta, gamma, and eta are...

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...

Homework Statement Recently I met a Mathcad calculation plotting bicycle path traveled. Initial positions of tire tracks are known, their increments were calculated with bike speed 'v', wheelbase 'p', and steering angle 'a' so via ODE system solving front and rear tracks coordinates were...

Homework Statement A ball is dropped straight down onto a wedge that is sitting on top of a frictionless surface. The wedge is at an angle of 45degreees and has a mass of 5.00kg. The ball has a mass of 3.00kg. If the ball collides with the wedge at 4.50m/s, and the collision is instantaneous...

Homework Statement A picture of the problem can be seen http://images3a.snapfish.com/232323232%7Ffp733%3B3%3Enu%3D52%3A%3A%3E379%3E256%3EWSNRCG%3D335%3B%3C6%3B737347nu0mrj". Original question: An archer is standing inside a long building whose ceiling is 11 m high. The archer can shoot and...

Hi, I'm trying to make a 2d simulation of elastic colliding balls. I have a hard time deriving the motion equations after collision. For each ball i know the speed, the mass and the angle of movement. Can anyone point me in the right direction to find the general equations for this ? I need the...

Hello everyone, Physion is a 2D Physics simulation program. It is quite difficult to explain its features and how exactly it works so please watch the videos below to get the main idea. https://www.youtube.com/watch?v=P32UHa-3BfU https://www.youtube.com/watch?v=GgbH7_Gc8fE Physion...

I am trying to use Gaussian elimination to solve the 2D poisson equation. I've done this for the 1D problem without problems, but for some reason my solution for the 2D problem is incorrect; it looks something like the correct solution but it's as if the resulting field were cut in half, so...

Vectors and 2D Kinematic Question! On the Apollo 14 mission to the moon, astronaut Alan Shepard hit a golf ball with a golf club improvised from a tool. The free-fall acceleration on the moon is 1/6 of its value on earth. Suppose he hits the ball with a speed of 25 m/s at an angle of 35° above...

Homework Statement A box containing a particle is divided into right and left compartments by a thin partition. We describe the position of the particle with a 2D space with basis states |R> and |L> according to whether the particle is in the right or left compartment. Thus, a generic state is...

An astronaut in his space suit can throw a ball a maximum distance dmax = 14 m on the surface of the earth. a) For a given speed of the ball, what angle to the horizontal q (in degrees) will yield the greatest range? q = 45 OK b) If the ball is thrown at this same angle q, what speed...

Homework Statement I need to derive the 2D N-S equations for steady, incompressible, constant viscosity flow in the xy-plane. I need to use a control volume approach (as opposed to system approach) on a differential control volume (CV) using the conseervation of linear momentum...

Hi I have an issue I am trying to solve, so far I haven't managed to get past it. I have some data for 200 points in theta from 0 to 2PI. The data is spherically symmetric so there is no phi dependence. Basically what I want to do is turn the 2D plot into a 3D by revolving the 2D plot. My...

Consider a 2D variable coefficient linear recurrence relation. An example might be: b_{n,j+1} (j+1)(2n-1)(2n-2) = (2n-2+j)(2n-1+j)b_{n-1,j} which has the solution b_{n,j} = \frac{(2n-1+j)!}{(2n-1)!j!} Is there any algorithm that can be used to derive this result? I have a recurrence...

Java Graphics & 2D Help me animate this! Instructions : Using Graphics and Graphics2D, create a neon sign for your business logo. Create your logo to include a shape and the name of your business. The logo should flash off and on continuously. You may get as creative as you wish with your...

Homework Statement A 2D flow is given by u = v/(1+t) , v = 1 Find the equation of the streakline at t=0 formed by releasing dye from the point (1,1) at t= 0Homework Equations u = dx/dt = v/(1+t) = 1/(1+t) -> (eq. 1) v = dy/dt = 1...

An explanation given to the question, "Why do I look different in pictures versus a mirror?", cited that in a picture one views a 2D image but in a mirror one views a 3D image. This difference can effect the depth perceived in ones face. Is this explanation valid? My take is that the...

Homework Statement A tennis ball is thrown from ground level with velocity vo directed sin 30 above the horizontal. If it takes the ball 1.0s to reach the top of its trajectory, what is the magnitude of the initial velocity? Homework Equations The initial vertical component of...

Homework Statement It can be shown that the allowed energies of a particle of mass m in a two dimensional square box of side L are E =h2(n2+m2)/8mL2 The energy depends on two quantum numbers, n and m, both of which must have an integer value 1, 2, 3... What is the minumum energy for a...

Homework Statement It seemed much easier to screencap than to write out. Homework Equations It helps to know that the number of states with speed between u and u+du is 2pi*u du The Attempt at a Solution I've tried quite a few things but every time I get to trying to normalise I either get...

Hi there, I was expecting to find a "simulations forums" somewhere here, if there is a better place for this thread please let me know :) OK, here's the problem: I'm trying to make a simulation with PYthon, at first with a square potential, for simpler potential/boundary conditions. But...

1. Hi, I am trying to model the magnetic force between two cylindrical identical sized permanent magnets. I am using the Charge/Coulombian model to do this. This assumes that all of the "magnetic charge" is on the pole ends of the magnet, i.e. the flat surfaces at the top and bottom of each...

hi every one I want an instruction file about design power transformer in Maxwell 2D and i want an instruction file about electrical circuit of power transformer in maxwell circuit editor please help me << e-mail address deleted by Moderator -- please use PMs instead >> please send me...

Homework Statement Hi everybody, I'm trying to solve the heat eq. for a 2D problem which is stationary, and also includes convection. There is no heat source. I am using Matlab. Homework Equations domain: x:0:1, y:0:1 u(x,1) = x(1-x) all other boundaries are 0 The Attempt at a...

Homework Statement There are three smooth stones in contact with each other at rest on an ice field (coefficient of sliding friction=0.0250). Their masses are: A = 0.800kg, B = 0.600kg and C = 0.250kg. An explosion causes them to fly apart. 'A' moves Due North with a Velocity = 2.40 ms-1...

It surprises me how much mathematics is needed to solve the innocent-looking 2D Ising model, and the Heisenberg model is quite an exercise even in 1D. I begin to doubt whether solving these models is really worth the effort, given that these systems don't look very realistic, and computer...

Homework Statement A 600g billiard ball moving to the right at 2 m/s collides with an 800g ball at rest. After the collision, the 600 g deflected at an angle of 37 degrees above its original direction at a rate of .5 m/. What is the magbnitude and diredction of 800g ball's velocity...

Homework Statement A football player kicks a field goal from a distance of 45m from the goalpost. The football is launched at 35 degrees above horizontal. What initial velocity is required so that the football just clears the goalpost crossbar that is 3.1m above the ground? ignore air...

Hi, I just saw this video on youtube, originally from Carl Sagan's 'Cosmos', about a 4th spatial dimension. http://www.youtube.com/watch?v=Y9KT4M7kiSw&NR=1" So what happens when the photons that are traveling in 3D hit an object in a 2D plane universe. To a 2D object it seems like photon...

Homework Statement u_{tt}=u_{xx} The Attempt at a Solution Where do I start? I have this wonderful Schaums outline at hand, and by looking at similar (unfortunately unsolved problems) I can guess that the answer will be in the range of: u=F(x+iy)+G(x-iy) I'm saying something in...

Does anyone know a good free library to do Fourier Transforms (FFT or DFT). I know FFTW but I'm having some problems with it. I want an alternative that do FFT in two dimensions with complex numbers. The libraries I have found doesn't fulfill this requirements. Thank you

Does anyone know a good free library to do Fourier Transforms (FFT or DFT). I know FFTW but I'm having some problems with it. I want an alternative that do FFT in two dimensions with complex numbers. The libraries I have found doesn't fulfill this requirements. Thank you

Homework Statement That's basically the whole question in the title there, ie; Derive an expression for the fermi energy of a 2d structure at 0 kelvin. 2. The attempt at a solution Basically the first part of the question had us sketching the Fermi-Dirac distribution function at 0K for...

Homework Statement heat equation of for 2 dimensional body(stationary)...heat is supplied to a body per unit volume and per unit time and by using conservation of energy principle the following equation is derived.. \intQt dA= \intqt d\ell the intergral on the right is a line integral on a...

Hi I'm looking for some help with trying to understand how to use the metropolis algorithm for the 2D ising model. In the problem i am trying to solve, the Hamiltonian is simply H= - sum(Si). I am given a probability function= exp[-H/T] / Z(T) where Z is the partition function which i found...

Homework Statement You are given in a earlier stage of this problem that the wavefunction is separable, ie.) \Psi(x,y) = X(x)Y(y) The problem asks you to solve for the wavefunction of a particle trapped in a 2D infinite square well using Parity. ie.) solve \Psi(-x,-y) = \Psi(x,y) and...

Homework Statement So, I'm in a 2D Euclidean space V. The two vectors v1 and v2 forms the orthonormal basis set for V. Consider the transformation T(v1) = a*v1 + b*v2, T(v2) = c*v1 + d*v2 Show, using scalar products (not vector products), that the area scale factor of the transformation T is...

Hi, Could someone help to explain that why for the 2 D system, like 2 dimensional electronic gas, the crystal momentum k in 2D band structure is defined on a torus? Thanks a lot.:)

This is similar to finding the net force of a moon around and planet and the planet around the sun but in perfect circular orbits in 2d without consideration for gravitational effects. Does anyone have a solution? If not there's a complicated paper that could be simplified from NASA in the...

Homework Statement Hi, I'm in a calculus base physics course in college so i thought this forum would be appropriate to post this question. The question is as follows: "A cannonball leaves the end of the cannon with an initial velocity of 67 m/s. Assuming a level terrain, at what angle(s)...