2d Definition and 1000 Threads

Suppose, I know the metric tensor of a 2D space. for example, the metric tensor of a sphere of radius R, gij = ##\begin{pmatrix} R^2 & 0 \\ 0 & R^2\cdot sin^2\theta \end{pmatrix}## ,and I just know the metric tensor, but don't know that it is of a sphere. Now I want to draw a 2D space(surface)...

Homework Statement A stone is thrown at an angle of 36.9 above the horizontal at 24.0 m/s from a building 56m high. What is the maximum height (with respect to the ground) that the stone reaches? Homework Equations - The Attempt at a Solution No clue. Have a picture drawn and all my knowns...

Homework Statement How do you calculate compute the the magnitude of the total force of three charges and also the angle it makes with the x-axis? Knowing the magnitude and also the 2d co ordinates of the charges. (x1,y1) (x2,y2) (x3,y3) I know for definite I use the below calculation but...

I can't compute the integral: \int \frac{\arccos(\sqrt{x^2+y^2})}{\sqrt{x^2+y^2}}\frac{x-a}/{(\sqrt{(x-1)^2+y^2})^3 dxdy on an unit circle: r < 1. for const: a = 0.01, 0.02, ect. up to 1 or 2. I used a polar coordinates, but the values jump dramatically in some places (around the 'a' values)...

Hello everybody. Although this is just a kinematics problem, I am having a hard time figuring out what to do. The question is: An archer on the planet zorg spots an octomorph that is resting in a tree above water. The octomorph's position in the tree is 100m away horizontally and 100m...

Homework Statement (a) the density of k-states g(k) = L^2*k/2*Pi. (b) the density of states g(E) = L^2*m/Pi*h^2 (c)The density of states per area n2D(E)=m*/Pi*h^2 (d) Sketch a graph of n2D(E) vs E. (e) Calculate n2D(E) as a quantity. The questions don't have to be answered in full a...

Given a warren truss, where the load is 2kN/m so the weight per joint is 10kN, since the ends are supported by ground not truss, can anyone please verify my way of solving for the tension and compression at point B. See attachment Your help is greatly appreciated. So I figured out that AB is...

Homework Statement Standard pool balls have a mass of 0.17kg. Before a collision, ball A is at rest and ball B is traveling at 4.5 m/s [N]. After the collision, ball B is traveling at 1.6 m/s [N20E]. What is the velocity of ball A? Homework Equations pinitial = pfinal m1v1 + m2v2 = m1v1 + m2v2...

Hi friends, i have developed an code for a non linear heat conduction in 2 dimensions with dirichlet boundary condition by finite difference method in Matlab. my code is running slow to give output. If anybody has any idea of solving this equation or have written any Code for this equation...

Hi. Can you do a computer simulation of a membrane with a standing wave(s)/node(s) with a shape of a cube or cone? It is possible on a string so why not on a membrane. Can you do a computer simulation of a spherical membrane with a standing wave(s)/node(s) with a shape of a cube or cone...

Homework Statement Firing something at 40m/s at angle X, it lands 65meters away, give 2 angles it could be.. (Assume g=10m/s^2)(Fired at y=0)(No air resistance) Homework Equations D = v^2/g sin(2x) [/B] The Attempt at a Solution d= v^2/g sin(2x) 65 = 40^2/10 sin(2x) 650/1600 = sin(2x)...

I'm struggling to do this problem. "When Babe Ruth hit a homer over the 7.0m -high right-field fence 120m from home plate, roughly what was the minimum speed of the ball when it left the bat? Assume the ball was hit 1.0m above the ground and its path initially made a 30∘ angle with the ground."...

Homework Statement Suppose \mathbf{u,v,w} \in {\rm I\!R}^2 are noncollinear points, and let \mathbf{x} \in {\rm I\!R}^2. Show that we can write \mathbf{x} uniquely in the form \mathbf{x} = r\mathbf{u} + s\mathbf{v} + t\mathbf{w}, where r + s + t = 1. Homework Equations Suppose \mathbf{a,b}...

Hello everyone, I would like to get ~200 MeV quasi-monoenergetic electron beam by doing 2D Particle-In-Cell simulation in bubble regime. The moving window dimension is 50x50 μm for x and y, the simulation mesh size is set 0.04x0.4 μm, each mesh includes 10 particles, laser wavelength is 800 nm...

For an image, higher the dimensions of image ,more is the resolution of the image.But is there any relation present between sampling frequency and dimensions of image? Also, Whether the Number of samples presents in an image is equal to product of dimensions of image?

Homework Statement The truck is to be towed using two ropes. If the resultant force is to be 910N directed along the positive x axis, determine the magnitudes of force F1 and F2 acting on each rope and the angle θ of F2 so that the magnitude of F2 is a minimum. F1 acts at 20° from the...

Homework Statement A large very powerful gun shoots a bullet that easily goes through a block. In the process the block is knocked off the post and falls to the ground. Which hits the ground first, the bullet or the block. Why? Homework Equations The Attempt at a Solution I am...

I was recently trying to test something out with the Riemann tensor. I used only 2 dimensions for simplicity sake. As I was deriving the Riemann tensor, I noticed that it looked as if all of the elements were going to come out to be 0 (which they all did). Therefore, this coordinate system is...

Homework Statement Let a particle of mass m moving in 2d space in a potential V (x, y) = -1/2 kx2 + 1/2 λ0 x2y2 + 1/4λ1x where k,λ0,λ1 > 0.At what point (x0, y0) is the particle in stable equilibrium? 2 marks Homework Equations ∂V/∂x=0 ∂V/∂y=0; ∂2V/∂x2 > 0;∂2V/ ∂y2 > 0 The...

So I have a boat going across a river (y-direction, north) 400m wide. I am trying to hit a target 75m in the positive x direction on the opposite side of the river. My boat will travel a velocity v. The river will provide a constant velocity of +0.5 (east) I am trying to find the angle a, north...

Hi all This question came up to me when I was playing a game called KSP (a space sim game): Given an initial velocity and starting altitude, how do you create a 2D Cartesian equation of the orbit of that projectile around earth? For example if I told you a projectile is traveling at a...

Is this a correct derivation of a relation between displacement of a particle with its terminal launch angle, velocity, and environmental gravity? Let the velocity of the projectile be denoted V_n. Let the terminal side of the launch angle with respect to the ground be denoted \theta. The...

You can use transfer matrix method for 2d Ising model. Is there a list of models for which this method could be of use. Such as classical Heisenberg perhaps? Or Potts?

Hello Forum, The 1D harmonic oscillator is an important model of a system that oscillates periodically and sinusoidally about its equilibrium position. The restoring force is linear. There is only one mode with one single frequency omega_0 (which is the resonant frequency). What about the...

Hi all, I was looking at previous exams and I saw a question with single slit diffraction. Please look at picture. So, this made me think: "Wow, I never thought single slit diffraction could be applied in 2D with one pattern horizontal and the other vertical." Then, I thought why is...

Dear kind helpers, actually I am not 100% sure whether this is the right place to post, as it is not a homework in the sense of an exercise sheet. But I think it could be because it feels pretty basic and that I should be able to solve it. Though I really searched for a solution but could not...

It's known that the Density of States in 2D is given by, g_2(E)dE = \frac{a^2m}{\pi\hbar^2}dE The density of states in 1D and 3D are as follows, g_1(E)dE = \left(\frac{a}{\pi}\sqrt{\frac{2m}{\hbar^2}}\right)\frac{1}{\sqrt{E}}dE g_3(E)dE =...

Homework Statement A two-dimensional isotropic harmonic oscillator of mass μ has an energy of 2hω. It experiments a perturbation V = xy. What are its energies and eigenkets to first order? Homework Equations The energy operator / Hamiltonian: H = -h²/2μ(Px² + Py²) + μω(x² + y²) The...

:confused: HI, is wave behaviour on a two dimensional field or in a multidimensional field in space?? i am currently conducting a study whether the object producing the wave is actually spinning and the resultant disturbance on the field it is residing causes the field to respond to the...

Hello, i had studied the problem in 1D, but i thinking the problem in 2d, an i have the following question: in a potential -V between (-a,a) an 0 otherwise. One dimensional case: One of the boundary condition are : ##\phi_I \in (-a,a)##, and ##\phi_{II} \in (a,\infty)## ##...

Say I have an N X N array of points, I would like a formula to give the mean distance between the points. There are lots of short distances but only two long ones (diagonal). There are plenty of algorithms to do this but I would like to work out a formula if there is one. Can someone point me in...

An antitank gun which fires missiles with a speed of 240m/s is located on a 60m high plateau overlooking the surrounding plain. The gun crew sights an enemy tank 2200m from the base of the plateau. Simultaneously, the tank crew sees the gun and starts to head directly away from the plateau. The...

Homework Statement I'm working on problem 1, specifically part (d) in the attached PDF file. I will show my code for (a) - (c) so you can see where I am coming fromHomework Equations The Attempt at a Solution (a) A1 = [1.3 5.2; 7.4 3.8; 9 2] A1 = 1.3000 5.2000 7.4000 3.8000...

Homework Statement Homework Equations The Attempt at a Solution A = [2.1, 4.2, 6.7; 8.3, 5.3, 5.4] A = 2.1000 4.2000 6.7000 8.3000 5.3000 5.4000 [mVal, I] = max(A,[],1) mVal = 8.3000 5.3000 6.7000I = 2 2 1 I don't understand what max(A,[],1) is...

Homework Statement Homework Equations The Attempt at a Solution Hello, I am having some confusion over the notation used in matlab. I don't really know what they mean A = [1:3; 4:6; 7:9] A = 1 2 3 4 5 6 7 8 9 A(1:2, 1:2) ans = 1 2...

Hi, How do you define number of turns in a coil designed to operate at 100 kHz? Maxwell 2D axisymmetric treats the coils as a single conductor, how can we define number of turns. I would appreciate any response. Thanks

Hello everyone ,i have captured car positons at differents frames.http://www.imagesup.net/pt-7140205392313.png%5D%5BIMG%5Dhttp://www.imagesup.net/dt-7140205392313.png Suppose car's(left side car which is coming towards us) centroid is at video frame1 is P(x1,y1) and Q(x2,y2) at video frame4...

This is sort of statics, but this came up in my physics class before. You have a plate, supported only in the middle by a simple support. So, this beam is balanced on the support, and is bending under it's own weight. What shape does the beam take? I was thinking either a inverted parabola or...

2D Fourier Transform on a non-rectangular area Is it possible to perform a Fourier transform on a shape instead of a rectangular region? To be specific I am attempting to make a linear zoom function that doesn't produce any pixelation and that mimics natural blur that occurs with distance...

Dear all, is there anybody knows how to set a 2 degree-of-freedom movement in ANSYS Maxwell 2D transient model? I have two fixed current-excited coils and a free magnet. The magnet should be able to move in a 2D space under the Lorentz forces. However, there are only translation and rotation...

Homework Statement bifurcation for the following 2D system: Homework Equations x'=ux−y+x^3,y′=bx−y The Attempt at a Solution I have got ux−y+x^3=0, y=bx, then x=0 and ±sqrt(b−u). But I don't how to continue to find the bifurcation?

Hi, I am trying to formulate a 2D model to calculate the temperature change over time in a composite material. The material consists of several layers, and is heated from all edges by a known temperature vs time profile. I was thinking of creating a finite element model. Can someone...

Homework Statement In a friendly game of handball, you hit the ball essentially at ground level and send it toward a wall 4.6 m away. The ball is hit with a speed of 20 m/s at 40 degrees above the horizontal. a.) At what height does the ball strike the wall? b.) Calculate the speed of...

Homework Statement https://scontent-a-sjc.xx.fbcdn.net/hphotos-prn1/t1.0-9/603671_1409914319284787_3441607163537875560_n.jpg Homework Equations conservation of total momentum M1V1+M2V2 = MtotVf The Attempt at a Solution I tried using the COTM as such: x...

Homework Statement A book of mass M = .55 kg rests on a table where the coefficient of static friction us = .45. A force, F = 4 N acts on the book at an angle of 15 degrees above the surface of the table. What is the acceleration of the book if the coefficient of kinetic friction uk = .23...

I am reading James Munkres' book, Elements of Algebraic Topology. Theorem 6.2 on page 35 concerns the homology groups of the 2-dimensional torus. Munkres shows that H_1 (T) \simeq \mathbb{Z} \oplus \mathbb{Z} and H_2 (T) \simeq \mathbb{Z} . After some work I now (just!) follow the...

Homework Statement Part (a): Derive Ehrenfest's Theorem. What is a good quantum number? Part (b): Write down the energy eigenvalues and sketch energy diagram showing first 6 levels. Part (c): What's the symmetry of the new system and what happens to energy levels? Find a new good quantum...

Umm what just happened? I understand as far as u=x+y and v = y/x and when he does the 2d curl. What I don't get is the step thereafter when he flips it. How does he know to flip it? Further, when he flips it wouldn't that make the dvdu inside the integral cancel and hence leave him with dxdy?

"2D slice of a 6D Calabi-Yau manifold", and other? Mathematically what does it mean to take a "2D slice of a 6D Calabi-Yau manifold"? Part of quote taken from the top of, http://en.wikipedia.org/wiki/Calabi%E2%80%93Yau_manifold Is there a finite number of slices of a 6D Calabi-Yau manifold...

Hi Im busy creating an application to simulation a rocket in orbit. I am having trouble as the results I am getting are incorrect. Could someone please check if I am using the correct method as stated below. Everything works on a 2d plane, and has a x and y coordinate and a x and y...