2d Definition and 1000 Threads

  1. J

    A How to calculate 2D Trilateration Step by Step

    I am trying to code Trilateration but I am not familiar with the math behind it. even though there is an explanation on Wikipedia in this link https://en.wikipedia.org/wiki/Trilateration and a almost better explanation in here...
  2. M

    Fourier Transform of a 2D Anisotropic Gaussian Function

    In an image processing paper, it was explained that a 2D Gabor filter is constructed in the Fourier domain using the following formula: $$ H(u,v)=H_R(u,v) + i \cdot H_I(u,v)$$ where HR(u,v) and HI(u,v) are the real and imaginary components, respectively. It also mentions that the real and...
  3. G

    I 2D Time dilation simulation with several clocks?

    Hi, I'm looking for some kind of simulation for time dilation where you can add several clocks to a 2D plane, synchronize them, give them velocities and accelerate them. For example to simulate the twin paradoxon including the acceleration necessary to (at least) one clock to reunite them. I...
  4. A

    MATLAB Crank-Nicholson in 2D with MATLAB

    I have the code which solves the Sel'kov reaction-diffusion in MATLAB with a Crank-Nicholson scheme. I would love to modify or write a 2D Crank-Nicolson scheme which solves the equations: ##u_t = D_u(u_{xx}+u_{yy})-u+a*v+u^2*v## ##v_y = D_v(v_{xx}+v_{yy}) +b-av-u^2v## Where ##D_u, D_v## are...
  5. A

    Position of electron motion 2D

    Homework Statement consider an electron traveling away from the origin along the x-axis in the xy plane with initial velocity vi= viî. As it passes through the region x = 0 to x = d, the electron experiences acceleration a = axî + ayj, where ax and ay are constants. For the case vi = 1.80 ✕...
  6. M

    Modeling 2D vs. 3D Flow in a Circular Pipe

    Hi everyone! I have the following problem. I have a two phase flow in a circular pipe and I want to model it. I need to decide and justify whether the model should be 2D or 3D. For the moment, I can say only one thing: considering z-axis in the length direction (that it is the dominant one) I...
  7. T

    B Calculating Orbital Velocity in 2D

    Hi! Imagine a planet is alone in a two dimensional universe. It has a mass mp. Suddenly, the planet's moon appears out of nowhere. It appears with a distance r from the planet, has a mass mm and velocities vx in the x-direction and vy in the y-direction. The distances rx and ry are also known...
  8. ChrisVer

    C/C++ Why Am I Getting Linker Errors When Using Const Methods in C++?

    I have the following class Vec2D: #ifndef Vec2D_H #define Vec2D_H class Vec2D { private: double fX; double fY; public: Vec2D(); Vec2D(double x=0, double y=0); ~Vec2D() {}; double const X(); double const...
  9. fluidistic

    Python How Can I Fix the IndexError in My 2D Ising Model Simulation?

    Hi people, I'd like to simulate a 2d array of atoms/ions under a magnetic field H via the Ising's model. I've read http://fraden.brandeis.edu/courses/phys39/simulations/AsherIsingModelReport.pdf to get an idea on how to proceed. I'm not sure I got the correct ##\Delta E## values though. I'm...
  10. R

    2D Laplace's equation with mixed boundary conditions

    This isn't homework but could be labeled "textbook style" so I'm posting it here. Homework Statement I'm trying to solve \frac{\partial^2 u} {\partial x^2} +\frac{\partial^2 u} {\partial y^2}=0 on the domain x \in [-\infty,\infty], y\in[0,1] with the following mixed boundary conditions...
  11. J

    Does Bose Condensation Occur in 2D?

    Hi, I was given the following question: Show that Bose condensation does not occur in 2D. Hint: The integral you will get when you write the formula for N is doable in elementary functions. You should find that that N ∝ ln(1 − e βµ). I do indeed find that N ∝ ln(1/(1 − e βµ)) ∝ ln(1 − e βµ)...
  12. Ben Wilson

    MATLAB Fourier transform of a 2D shape

    I have a function of 2 variables [f(x,y)] where if there was an ellipse in the x-y plane, all values of the function are 1 inside the ellipse and 0 outside. I can plot this function as a surface in 3d where it looks like an elevated ellipse hovering over an elliptical hole in a sheet. My...
  13. S

    A Finite Difference solver for 2D Elasticity equations

    Hi I've been trying to get a simple solution to the 2D Navier-Lame equations using finite difference on a rectangular grid. I want to see the displacements, u and v, when a simple deformation is imposed - e.g. top boundary is displaced by 10%. The equations are as follows: \begin{eqnarray*}...
  14. T

    2D Kinematics - Dropping object from a zipline

    Homework Statement A 50m zipline is hung 11m off of the ground at its starting point (assume it ends at ground level). If you are to drop an object which is 20m along the ground from the start of the zipline, how far down the line would you need to let it go? Homework Equations d=((VF+VI)/2)*t...
  15. N

    Mysterious Misty Rings: Unraveling the 2D View

    The other morning it was misting. In the yard the nightlight glowed. Around it the pulsing AC was visible as it appeared to make small rings that moved outward directly, the observers(like an electron as it gets more excited for ex.) We also noticed that the image/rings appeared to be only two...
  16. abdulsulo

    Fortran How to Write a 2D Array to a .dat File in Fortran90?

    Hello everybody, I have a source code which gives me as a result an array of 2 columns and 3001 rows (2d array). By using fortran90. I was trying to have the values inside these cells into .dat file and tried to generate a subroutine and call my main array inside this. But somehow I get...
  17. S

    Insight/Intuition into rotations in R²

    I've been using rotation matrices for quite some time now without fully grasping them. Whenever I tried to develop an intuitive understanding of... x' = x\cos\theta - y\sin\theta \\ y' = x\sin\theta + y \cos\theta ... I failed and gave up. I've looked at numerous online texts and videos, but...
  18. F

    Working out force from distance object is displace (2D)

    This is a followup for my project which has been on a previous forum post: https://www.physicsforums.com/threads/wind-tunnel-measurements.856773/ I'm now trying to work out the forces on the object when under the influence of a 2.5m/s air speed and also knowing the mass of the object. My wind...
  19. I

    2D Relative Velocity regarding boats

    Homework Statement A boat propelled so as to travel with a speed of .5m/s in still water moves directly across a river that is 60m wide. The river flows with a speed of .3 m/s. At what angle relative to the straight across direction must the boat be pointed? How long does it take the boat to...
  20. K

    MHB Put the 2D nonlinear system into Polar Coordinates

    Show that, in polar coordinates, the system is given by r′ = r(r^2 − 4) θ′ = 1x′1 = x1 − x2 − x1^3 x′2 = x1 + x2 − x2^3
  21. K

    Deriving the Formula for 2D Motion with Constant Acceleration

    1. Homework Statement how to get R=Vi 2 sin2θ/g y=x*tanθ-[x2*g]/[2(Vi*cosθ)2] Homework Equations Vy=Vi*sinθ-gt y=Vi*sinθ*t-1/2gt^2 Vx=Vi*cosθ x=Vi*cosθ*t The Attempt at a Solution I use this formula to find the expression for t Vy=Vi*sinθ-gt gt=Vi*sinθ t=Vi*sinθ/g I substitute it into...
  22. aimen khattakk

    Solving 2D Momentum Collision: What is the Final Velocity After Collision?

    Homework Statement One car of mass 1400 kg is traveling at 45km/h when it collides and becomes entangles with another car mass of mass 1300 kg traveling at 39km/h[E]. What is their velocity after collision So MA = 1400 kg VA = 45kh/h MB = 1300 kg VB = 39 kh/h [E] and After Collision: MAB =...
  23. T

    Solve 2D Elastic Collision Homework Statement

    Homework Statement Problem: An object of mass m1 elastically collides with an object of mass m2 =(3/2) m1 that is initially at rest. The less massive object has speed v1 and travels at an angle of θ1with its original direction (x-axis) after collision; the more massive object has a speed of v2...
  24. Einstein's Cat

    Can an n-dimensional object fit entirely in n-1 dimensions?

    I am concerned that this question may instead be a philosophical one although if it it mathematical, any insights would be very appreciated. The question is this; could an object of N dimensions exist entirely in N-1 dimensions? In other words, could an infinitely flat object have 3 degrees of...
  25. D

    2D Elastic Collision Using Conservation of Momentum

    Homework Statement Two objects collide and bounce off one another. After the collision, object m1 = 2.74 kg moves off at 12.8 m/s at a heading of 295 degrees. Object m2 = 2.28 kg moves off at 12.8 m/s at a heading of 241 degrees. Initially, m2 was traveling at 11.1 m/s at a heading of 334...
  26. D

    Series expansion for 2D dipole displaced from the origin

    I learn that we can expand the electric potential in an infinite series of rho and cos(n*phi) when solving the Laplace equation in polar coordinates. The problem I want to consider is the expansion for the potential due to a 2D line dipole (two infinitely-long line charge separated by a small...
  27. Tabasko633

    2D Harmonic Oscillator Quantum numbers

    Homework Statement In the exercise, we solved the 2D Harmonic Oscillator in kartesian (x,y) and polar (r,φ) coordinates. We found out that both have the same energy levels, but they look very different, when I plot them. What am I missing? The polar solution seems more like it. Homework...
  28. J

    Projectile trajectory problem with constraint

    Homework Statement http://imgur.com/RDMG4Pj Link to drawn out problem^ The ball goes through the hoop NOT at the peak, but rather on it's downward path. It's asking for the total x-displacement, launch angle (theta), and the total flight time. It must me solved WITHOUT using the range...
  29. Devraj Dutt

    ANSYS Maxwell Optimetrics Error Handling

    A common problem with optimization of machines is that occasionally, some of the variable combinations will not be geometrically feasible. For example, if magnet angle is being parameterized in an IPMSM, it might be that at some point, the magnet skews so much that it juts out of the rotor...
  30. RJLiberator

    Comp Sci C++ (ROOT) Form a matrix and send it to a 2d Histogram

    Homework Statement [/B] 1. I've been tasked with forming a 10 x 10 matrix with elements 0, 1, 2, 3, 4, 5,... and have it display properly. 2. Then, take this matrix and make a 2d-histogram out of it. Homework Equations Here is my code void matrix6( const int n = 10) { float I[n][n]; //...
  31. M

    Using complex description of div and curl in 2d?

    In trying to get an intuition for curl and divergence, I've understood that in the case of R2, div f(x,y) = 2Re( d/dz f(z,z_)) and curl f(x,y) = 2Im( d/dz f(z,z)), where f(z,z) is just f(x,y) expressed in z and z conjugate (z). Is there any way of proving the fundamental properties of div and...
  32. J

    Answer "Solving 2D Elastic Collision Homework

    Homework Statement A 2.0 kg ball moving with a speed of 3.0 m/s hits, elastically, an identical stationary ball. If the first ball moves away with angle 30° to the original path, determine: a. the speed of the first ball after the collision. b. the speed and direction of the second ball after...
  33. stvrbbns

    2D - What is the next point given this info.

    In a two-dimensional environment: Given: a starting point (x1,y1) an initial velocity (speed and 2D heading/direction) a constant rate of turning (yaw, since there is no roll or pitch in only two dimensions) a constant acceleration of the object from itself (not like gravity where the direction...
  34. T

    Why Does Light Intensity Decrease with x^4 in 2D Fraunhofer Diffraction?

    Hello, My name is Thibaut, I am a student in physics and I currently struggling with something that some of you might find obvious. I did an experiment with a laser 650nm passing through a 2D squared grid. The light interferes and diffracts and a photomultiplier collect only the central spot...
  35. C

    Discrepancy with Toricellis equation in a 2D kinematics prob

    Homework Statement A stone is thrown from a height 2.1m with an angle of 45 degrees. It fell to the ground 42 m from the throwing position, measured horizontally. Initial velocity is 19,81 m/s, flight time is 3s what is the maximum height? Homework Equations All 2D kinematics equations. The...
  36. C

    Using series in a 2D kinematics problem

    Homework Statement A ball is rolling towards a rectangular hole which is 40cm deep and 2cm wide with a velocity 1m/s. It falls through the hole, bounces off the walls a couple of times and falls down. The direction of balls motion is perpendicular to the hole (falling in it from one side)...
  37. Negus

    Speeds regarding 2D inelastic collision

    Homework Statement You are called to the site of a collision between a small car and a half ton truck on a lonely country road. You are given the following information: a) On clean dry pavement at a temperature of 20 C, the coefficient of kinetic friction is 0.600 on locked wheels. b)...
  38. P

    Gravity Simulator 2D: Calculating Trajectories

    I want to create a simple 2d Gravity simulator where I have a large body i.e. A circle which could be a planet or the sun. I then want to simulate small comets or asteroids traveling past it, crashing into or being pulled into orbit. I know the gravitational force formula but that seems the...
  39. seyfi

    How to Implement the ADI Method for a 2D Heat Equation in Matlab?

    Hi all Do you know how to write code Alternating Direct Implicit(ADI) method in Matlab? I have given 2d heat equation for this. Thank you
  40. J

    Dealiasing in 2D: How to Effectively Use the 2/3 Padding Rule

    Hi, I would like to use the 2/3 padding rule for the dealiasing. In 1D, it's straightforward. For 2D, do I just have to set the highest 1/3 frequency components zero in both directions? For example, I ffted a 7*7 real data in Matlab, then I set the 4th and 5th columns and rows (corresponding...
  41. V

    Solve Elastic Collision: 2D Homework

    Homework Statement A red and a blue rubber puck are free to slide along a frictionless air table. Each has a mass of 40 grams. They collide in an elastic collision. Initially the red one is at rest and the blue one is traveling in the x direction with a speed of 4 m/s. After the collision the...
  42. S

    What is the difference between psi(x;y) and psi(x) in 2D BO

    What is the difference between psi(x;y) and psi(x) in 2D BO approximation for particle in a box. how to show psi(x;y) in MATLAB
  43. D

    Equilibrium in 2D: Finding Tension and Support Reactions in a Cable System

    Homework Statement A pole supporting a pedestrian and traffic light is shown. Neglecting the weight of the cables. Find the tension in the cables and and the support reactions at A,B,E. Mass of traffic signal 20kg Mass of pedestrian signal 10kg Mass of beam BCD 5kg center of gravity C Mass of...
  44. M

    What Are the Final Velocities of Hockey Pucks After a Glancing Collision?

    Homework Statement Two equal mass hockey pucks undergo a glancing collision. Puck 1 is initially at rest and is struck by puck 2 traveling at a velocity of 13 m/s[E]. Puck 1 travels at an angle of [E18N] after the collision. Puck 2 travels at an angle of [E4S]. Determine the final velocity...
  45. J

    How do I model a spring in Ansys 2D for a linear generator?

    Hi friends, I am working on a model of linear generator. I have modeled the linear generator in Ansys 2D. Now I want to attach a spring to one end of the rotor and see how it works with the spring attached to it. How do I model the spring? Also is there any proper way to determine the damping...
  46. E

    MATLAB 2D diffusion equation, for matlab code.

    https://scontent.xx.fbcdn.net/hphotos-xtf1/v/t34.0-12/12204847_801668796608594_2127169351_n.jpg?oh=f6ea92a40c93e4d843a4bf26a358677d&oe=56404FC5
  47. Z

    QM: commutator 2D particle magnetic field

    Homework Statement I was reading this textbook: https://books.google.com/books?id=sHJRFHz1rYsC&lpg=PA317&ots=RpEYQhecTX&dq=orbit%20center%20operators&pg=PA310#v=onepage&q=orbit%20center%20operators&f=false Homework Equations In the equation of the page (unlabeled), we have $$...
  48. C

    How to Compute the Propagator in 2D Euclidean Space?

    Homework Statement Consider the following scalar theory formulated in two-dimensional Euclidean space-time; S=∫d2x ½(∂μφ∂μφ + m2φ2) , a) Determine the equations of motion for the field φ. b) Compute the propagator; G(x,y) = ∫d2k/(2π)2 eik(x-y)G(k). Homework Equations Euler-Lagrange equations...
  49. Chrono G. Xay

    Can't Find 2D Elastic Modulus Equation

    I've tried searching online for one in what I can only guess would be called a reduced algebraic form, and I cannot find it. To make matters worse, for me, at least, I do not have the mathematics knowledge necessary to understand advanced functions, series, and transformations of mathematics...
  50. J

    Deriving Kinematics Equations from First Principles

    Homework Statement For an upcoming test on 2D Motion, my Physics Teacher recommended that, instead of memorizing close to a dozen equations, he suggested we derive what we can from the main equations he showed us. So people in my class decided to split up deriving equations to bring them...
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