2d Definition and 1000 Threads

Hi everyone! I don't know how to solve the next problem, and if anyone could explain to me step by step how it is solved I would thank you a lot. I know it's not hard, but I'm not seeing how to do it. Thank you in advance!

The question I am trying to solve is what is the velocity vector (direction and magnitude) of an object in 2 d space. We know the distance measured to the car from two different angles. We know the radial velocity of the car on both measurements. The radial velocity is the component of the...

Xcomp: [-(1500kg)(100km/h)(sin(30))+(3500kg)(70km/h)(cos(90))]/5000kg = -15km/h ycomp: [(1500kg)(100km/h)(cos(30))+(350(70km/h)(sin(90))]/5000kg = 74.98km/h

Hi everyone! Both sources I'm currently reading (page 291 of Mathematical Methods of Classical Mechanics by Arnol'd - get it here - and page 202 of Classical Mechanics by Shapiro - here) say that, in the case of the planar harmonic oscillator, using polar or cartesian coordinate systems leads...

Answer is 37.8 g cm^2 new to latex

I learned about Bessel functions and steady-state temperature distributions in the past. Recently, I was searching online for some example problems on the topic and found the "original question" along with the solution online as a PDF file. While I am unsure will it be appropriate for me to...

Hi all, I'm working on programming a simple 2D method of characteristics program to design the nozzle wall contour for a supersonic rocket nozzle. I'm wondering roughly what sort of difference I should expect from a 2D vs 3D method of characteristics program and where I could find a good...

Hii Friends. I was trying to model an Induction motor in ANSYS Maxwell 2D. The final output of Transient torque (negative torque) looks like shown below. The input passed is a sine wave current with 120 deg phase shift. Any Suggestion will be highly appreciated

Consider a slope with mass, that can move in the horizontal plane without friction. A ball is dropped and hits the slope with restitution coefficient e. How to calculate the final velocities? How can I solve something like this? Note that it's not a simple 2D collision, it has a restriction...

When we try to explain different dimensions we say that higher dimension beings have control over lower dimension beings. If a sphere moves trough a 2D world, the 2D beings will see a dot appear followed by a line which is increasing in size. Thereafter, the line decreases in size and becomes a...

Let's say you have a simple structure with two equal masses connected by a massless rigid baton of length L. Like this: Imagine this structure is totally free in space. It is not hinged in any way. Then forces act on each mass in 2D (x,y). If you have the x and y force vectors acting on each...

Too dim for this kind of combinatorics. Could anyone refer me to/ explain a general way of approaching these without having to think :D. Thanks.

In 2D modules, the 3rd direction isn't shown in model settings. What assumptions are made regarding electrostatics 2D modules? For example, how is a 2D Poisson's equation with point sources solved? Is it based on a 1/r potential or a log potential?

I ultimately want to make a sewing pattern of a ball. If I have an n-hosohedra, how do I figure out the equation of the curves that make up each lune in 2D?

For getting the density of states formula for photons, we simply multiply the density of states for atoms by 2 (due to two spins of photons). I am getting the 2D density of states formula as :- g(p)dp = 2πApdp/h^2 I think this is the formula for normal particles, and so for photons I need to...

Hi! Situation: quasi-free electron in a 2D lattice, considering atomic potential V(r) = exp{-|r|/b} (r is the distance from the atom) I'm trying to compute the first five energy gaps at point (10), firstly I don't understand the meaning of calculated 5 energy gaps at one point and usually we...

How do I get the wave dispersion for a 2D continuum unit cell subjected to a periodic boundary which is excited longitudinally? I'll be applying forces in ABAQUS with varying frequencies. I have come across Blochs theorem but I can't find any application of it in continuous systems. Every...

Suppose that I have the coordinates of x and y on a plane. I am writing a piece of software where the user can select a polygon of 3, 4, 5, 6 or 8 sides. All of the polygon points are equidistant from the x, y point. In other words, if you drew a circle where the center was the x, y point, all...

What's the best software to use when designing 2D floor plans for structures?

Hi PF! Do you know what the natural oscillating frequencies are for a 2D circular drop of liquid in an ambient environment (negligible effects)? Prosperetti 1979 predicts the frequencies for both a spherical drop and bubble here at equations 5b and 6b. There must be a simpler circular 2D...

I am unable to find any angle for which the horizontal and vertical components of the linear momentum are conserved. I have added an image of my attempt

I know this topic was raised many times at numerous forums and I read some of these discussions. However, I did not manage to find an answer for the following principal question. I gather one deals with the same set in both cases equipped it with two different structures (it is obvious if one...

Dear experts, How would I find the forces for the truss with both ends pinned? (Fig.1, bottom) I'm trying to determine the forces in all members of some trusses. I've successfully applied the method of sections to a Howe truss (top truss in Fig.1) and I' ve verified it by FEA with MecWay...

import matplotlibimport matplotlib.pyplot as plt import numpy as np from sklearn import datasets, linear_model import pandas as pd # Load CSV and columns df = pd.read_csv("C:\Housing.csv") Y = df['price'] X = df['lotsize'] # Split the data into training/testing sets X_train = X[:-250] X_test =...

Hi, I've been given a homework to do based on 2D Ising model. Ive already read plenty of articles bout 2d ising model but I'm not fairly certain about some things. I got to do a chart similar to the one I attached. Correct me if I am wrong, but on the Y axis, I have to put average of...

Pardon if the answers to my questions are obvious, because as usual I am trying to decipher everything on my own (as the material has not been taught to us quite well; then again it's graduate school). I just need someone to reassure me that I am understanding this correctly. Say for example I...

Hi all, Sorry, in my first message, I posted this question in the Basic Probability section, and so I moved it to this section. I have a surface (for example, a blank paper). In this surface, I have some elements of the set "A" randomly distributed. In this surface, I also have some elements...

Which could be the first step to find the V(t) ?

## \int_{-1}^{1} \int_{-1}^{1} e^{-(x^2 + y^2)} cos(2π (x^2 + y^2)\,dx\,dy ## ## I = \int_{-1}^{1} \int_{-1}^{1}f(x,y) \,dx\,dy \approx \sum_{i=0}^{n}\sum_{j=0}^{n} w_i w_j f(x_i, y_j) ## ## = w_0 w_0 f(x_0, y_0) + w_0 w_1 f(x_0, y_1) + w_1 w_0 f(x_1, y_0) + w_1 w_1 f(x_1, y_1) ## ## w_0 =...

We have a 2D box (billiard table) which have size of Width = 600 and Height = 300. We have two identical ball a radius of 20. Also the balls decelerate with a rate of 5 m/s^2. The problem is to find the position of the ball after 10 second. ( The balls may have collide) from math import...

So ##T+U=\frac{1}{2}m(\dot{x}^{2}+\dot{y}^{2})-mgy=constant##. If I derive this with respect to ##t## $$\dot{x}\ddot{x}+\dot{y}\ddot{y}-g\dot{y}=0$$ Then I use ##\dot{y}=\dot{x}\frac{dy}{dx},\ddot{y}=\ddot{x}\frac{dy}{dx}+\dot{x}^{2}\frac{d^{2}y}{dx^{2}}## to get...

I'm tasked with drawing the trajectory of the Moon around the Earth (in 2D), taking into account the fact that the trajectory also undergoes precession, so the elliptical orbit rotates about it's center (I think it should rotate around the Earth-Moon barycenter, but for the first step I...

I have calculated the normalization constant, but I'm struggling with the discontinuities in the derivatives of the wave function. Due to the symmetry, it should suffice to consider the first two cases. The results should be (according to WolframAlpha): \left( \frac{\partial^{2}}{\partial...

Summary: How to explain the focusing properties of a 2D parabolic mirror based on third-order aberration theory? Hello everyone, I am currently studying with full-wave simulations the focusing properties of a 2D parabolic mirror, i.e. the scattered fields resulting from plane wave incidence...

I just tried to find the eigenvalues (for the energy), obtaining E = ±(γħ.√(Bo² + Γo²))/2 and the corresponding eigenvectors for the H matrix. But I don't know what to do to create de state vector χ.

Hi I have a 2d trajectory of a center of mass which I have saved in an array such that r=[[x(t_1),y(t_1)],[x(t_2),y(t_2)],...,[x(t_n),y(t_n)]] where x is x coordinate of the position and y is the y-coordinate of the position. I have tried this: xx = [t[0] for t in r] xy = [t[1] for t in r]...

Since in 2D the riemman curvature tensor has only one independent component, ## R = R_{ab} g^{ab} ## can be reversed to get the riemmann curvature tensor. Write ## R_{ab} = R g_{ab} ## Now ## R g_{ab} = R_{acbd} g^{cd}## Rewrite this as ## R_{acbd} = Rg_{ab} g_{cd} ## My issue is I'm not...

I am trying to understand ergodic theory, i.e. how simple systems reach equilibrium. I consider a classical particle in a 2D (or 3D) box. Funnily, I have never seen this example in books (probably due to lack of knowledge). Instead, in QM, the particle in a box is a prototypical example. My...

Hi, My other post got deleted because it was flagged for spam, but it was just a link to a pdf. So I'm uploading the pdf instead. I am working on a model to predict drag on airfoils in 2D potential flow (e.g. vortex panel methods). Currently, XFOIL uses a semi-empirical wake-momentum-thickness...

My only issue is what this would look like. I can't draw a respective picture.

Homework Statement A baseball is hit into the air, nearly vertically, with a speed of 27 m/s. When it comes down, the ballplayer catches it in his glove. Air resistance (drag) is actually fairly important for a baseball in flight, but for now let’s assume it is negligible. (a) How high does...

If considering a 2D surface (plane) having polar coordinate r,θ (where r is the distance from the origin and θ is the anticlockwise angle from the base line as usual) The metric is now actually ds2=dr2+r2dθ2 If now this 2D surface is given a positive curvature of +1 (equivalent to the surface of...

Tomorrow is my math test and I'm going over the study guide: I have vector U=<1, 3> and vector V=<5, 2> It says let theta be the missing angle between the two vectors. What is the cos(theta) and sin(theta)? I already know how to find the missing angle for cos(theta) but we never covered how...

Homework Statement Solve the following partial differential equation , using Fourier Transform: Given the following: And a initial condition: Homework EquationsThe Attempt at a Solution First , i associate spectral variables to the x and t variables: ## k ## is the spectral variable...

Homework Statement An atomic nucleous of mass m traveling with speed v collides elastically with a target particle of mass 3.0m (initially at rest) and is scattered at 45o (a). What are the final speeds of the two particles? Advice: eliminate the target particle's recoil angle by manipulating...

Homework Statement Find the eigenfunctions and eigenvalues of the isotropic bidimensional harmonic oscillator in polar coordinates. Homework Equations $$H=-\frac{\hbar}{2m}(\frac{\partial^2}{\partial r^2}+\frac{1}{r}\frac{\partial}{\partial r}+\frac{1}{r^2}\frac{\partial^2}{\partial...

I'm sorry if this question is a little abstract, but would appreciate any guidance! It's for a DIY project I am considering. Suppose you have a flat panel mounted on a wall, and a very strong magnet that will move in any direction on the plane of the flat panel. Through any possible arrangement...

Hello, I am working on a map generator for a game called Dominions. I plan to make it open source once it's functional. Maps in this game typically wrap vertically and horizontally, so the generator must create maps that seamlessly wrap on the X and Y axis. Typically (for even player counts)...

Hi guys, On with my Fortran adventures...I'm trying to accomplish a simple task: assign a 2D array with some reals. Here's an excerpt from the code: subroutine get_energy_and_grad(natoms_,coords,ereal,gradmat) include 'cbka.blk' include 'opt.blk' integer, intent(in) :: natoms_...