1d Definition and 383 Threads

Let's suppose that we have two point particles with masses m1,m2 and the spherical shell with mass M, placed in a line, at distances h1,h2 and H from 0 in that line (0 is the center of some inertial frame of reference). The initial conditions and the equations of motion are the following...

Is a curve (Say 'S') 1d or 2d? I ask this question because for so long i was under the impression that it was 2d, since we need a 2d cartesian plane to draw and describe a curve. But then i read in a popular book that it was 1D, which is hard to believe. so which is it?

I am trying to write a solver for a 1D wave equation in MATLAB, and I have run into interesting problem that I just can't find a way out of. I start with the wave equation, and then discretize it, to arrive at the following, U{n+1}(j)=a*(U{n}(j+1)-2*U{n}(j)+U{n}(j-1))+2*U{n}(j)-U{n-1}(j)...

Homework Statement This is from an old exam I'm studying from. It goes: "A particle of mass m is traveling in one dimension under the influence of a potential V = -Fx where F is a known constant. Find the energy spectrum and wavefunctions. Hint: You may want to work in momentum...

Homework Statement Three charges lie along the x-axis. The positive charge q1 = 10.0 x 10^-6 C is at x = 1.00 m, and the negative charge q2 = -2.00 x 10^-6 C is at the origin. Where must a positive charge q3 be placed on the x-axis so that the resultant force on it is zero? Homework...

Homework Statement I have been asked to model the flow of a slightly compressible liquid through a rigid, incompressible porous medium in 1D, assuming the flow obeys Darcy's law. I am given a rectangular prism of cross sectional area A with length L, a source of liquid (say water) on one...

QED in 3D --> QED in 1D, what changes? Can we have massive charged and massless fields which interact in one space dimension? What might the interaction term look like? Thanks for any help!

1D Potential 1. Homework Statement Given: U(x) = U_0 - U_n*e^-(kx^2), U_0, U_n and k are all constant. i) What is the maximum E for the particle to remain in potential? ii) Show that the potential has a minimum at x = 0. iii) If a particle of mass m is placed near the minimum at x = 0, and...

Hello, I am trying to solve a 1D heat analysis problem for an electric generator. The stator or the device icludes the copper which is well insulated and is cooled from the left using water running through a pipe. The rotor is made of magnets supported by an iron frame. Cooling air is blown...

Hi, I have a pseudocode I would like to try and implement and understand the programming of it in python. The physics and maths of the case is no problem, but the implementation of the code in Python is something I'm not familiar with. The problem is a simple 1D linear convection using...

Ok, so I am trying understand how to derive the following version of the Schrodinger Equation for QHO: \frac{d^2u}{dz^2} + (2\epsilon-z^2)u=0 where \ 1. z=(\frac{m\omega}{hbar})^{1/2}x and \ 2. \epsilon= \frac{E}{hbar\omega} I've started with the TISE, used a potential of...

Hello, I am reading a book about finite elements with regards to stress analysis. I'm pretty sure the book is full of mistakes, which makes following and doing the examples fairly difficult. I have posted a 1D analysis from the book, I'm not even sure how he comes up with some of the numbers in...

1D advection-diffusion--need to check my code; any suggestions? Hi everyone: I am teaching myself transport/programming, and have created a simple program for 1-D advection-diffusion (constant velocity, diffusion coefficient, central differencing, Crank-Nicolson). I would like to check...

Hello--- I am reading a paper which presents a method to determine attenuation (and Q factors) from reflection seismic data (Y. Wang, "Q analysis on reflection seismic data," Geophysical Research Letters, Vol. 31, 2004). To perform signal processing on a seismic trace, the paper describes...

Hi all, I was wondering whether there was any work done on a random walker on a 1D lattice with diffusing boundaries? Any links or suggestions would be great!

Homework Statement Two identical positive charges of +Q are 1 m apart. What is the magnitude and direction of the electric field at point A, 0.25 m to the right of the left-hand charge? Homework Equations E = kQ/r^2 The Attempt at a Solution I summed up kQ+/(.25^2) and...

So in one of my classes, we very non-rigorously derived the 1D stress field for a bar with a longitudinal surface loading T(x) like show below: By taking out a differential element (assuming constant cross-sectional area) and applying good old Newton's Second, we end up with: A...

Hello all, This is to do with forced longitudinal vibration of a rod (bar). It's basically a problem to do with the linearised plane wave equation (1d). The rod is fixed firmly at one end, and excited at the other by a harmonic force. The wave equation (with constant rho/E instead of...

Homework Statement Two identical non-interacting spin 1/2 particles are in the one-dimensional simple harmonic oscillator potential V(x) = kx2/2. The particles are in the lowest-energy triplet state. a. Write down the normalized space part of the wave function. b. Calculate the energy of...

I Have a brief idea about the equation and i have searched the web for its application to one dimensional harmonic oscillator but no use. Any Help Would Be Welcomed Especially about the latter:smile:

Homework Statement Determine the probability of finding a particle in a 1-D box of size L in a region of size 0.01L at the locations x = 0, 0.25L, 0.5L, 0.75L and L when it is in its ground state. As percentages Homework Equations \Psi(x)=\sqrt{\frac{2}{L}}sin(\frac{nxPI}{L})...

Hi, I'm looking for a solution to u_t + A u_x + B (u - f) = 0 where f is a given function linear in x and constant in t. u(x,0) = f(x) u(0,t) = f(0) A and B constant. Does this equation have a name? It's almost the inviscid Burger, but has the damping term (B u) and force term...

Hi Most of my work in the past has been on 1D independent particle systems where I use matrix diagonalisation to solve the time-independent Schrodinger equation. How do I go about this for 2D? Or, more accurately, for a two-body wf in 1D? It strikes me as straightforward to construct a...

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Homework Statement A car making a 94-km journey travels 39 km/h for the first 47 km. How fast must it go during the second 47 km to average 51 km/h? Homework Equations The Attempt at a Solution

Homework Statement I have a charged particle in a 1D harmonic oscillator, on which an externally applied electric field acts, such that the Hamiltonian can be written: \frac{p^2}{2m}+\frac{kx^2}{2}-qEx The problem asks to first find the first (trivial) and second order corrections to...

I studied in AMO physics. nowaday, I study about BEC. I'm wonder, Difference between 1D lattice and 2D lattice on BEC. In the web, they just explain what they do using that. Maybe just short word, or sentence, give me a huge knowledge. Thanks you, and Have a nice day!

Homework Statement I believe this is a pretty standard question. A particle is initially in the ground state of a box of length L. Suddenly, the box expands symmetrically to twice its size, without disturbing the wavefunction. Show that the probability of finding the particle in the ground...

Homework Statement Find the eigenvalues and eigenfunctions of H\hat{} for a 1D harmonic oscillator system with V(x) = infinity for x<0, V(x) = 1/2kx^2 for x > or equal to 0. Homework Equations The Attempt at a Solution I think the hamiltonian is equal to the potential + kinetic...

Homework Statement Alright, well this is more of a math problem I guess... but here it is. \frac{\partial^{2}}{\partial x{2}} V = - \frac{I}{A\epsilon_o} \sqrt{\frac{m}{2e}} \frac{1}{\sqrt{V}} Everything besides the V is constant. Homework Equations Trying to solve for the potentialThe...

Homework Statement A model rocket blasts off from the ground, rising straight upward with a constant acceleration that has a magnitude of 76.0 m/s2 for 1.54 seconds, at which point its fuel abruptly runs out. Air resistance has no effect on its flight. What maximum altitude (above the ground)...

Homework Statement Problem taken from Cutnell & Johnson 8th Edition Textbook (though it's also in the 7th edition as well, can't recall question # though). It is from chapter 2, question # 10. In reaching her destination, a backpacker walks with an average velocity of 1.34 m/s, due west...

1. A stone is thrown with an initial velocity of +7.0 m/s. The acceleration of the stone is a constant and has the value of -9.81m/s^2.What is the velocity of the stone after 0.5s? 2. Homework Equations vf=vi+at? i have no idea 3. The Attempt at a Solution...

Homework Statement A jetliner leaves San Franciso for New york, 4600 km away. With a strong tailwind, its speed is 1100 km/hr. At the same time, a s2nd jet leaves New York for San Francisco. Flying into the wind, it makes only 700 km/hr. When and where do the two planes pass each other...

In reaching her destination, a backpacker walks with an average velocity of 1.31 m/s, due west. This average velocity results because she hikes for 6.44 km with an average velocity of 2.54 m/s, due west, turns around, and hikes with an average velocity of 0.475 m/s, due east. How far east did...

Homework Statement A car traveling at a constant speed of 108 km/hr passes a trooper hidden behind a billboard. One second after the speeding car passes the billboard, the trooper sets in a chase after the car with a constant acceleration of 3.0 m/s2. How far does the trooper travel before he...

Homework Statement An object falls from height h from rest. If it travels .5h in the last second before hitting the ground, determine how long it takes to fall and the height h. xi = .5hm, t =1s, a = 9.8m/s^2, xf = 0m, Homework Equations Vf = Vi + at xf = xi + .5at^2 The Attempt at a...

Homework Statement The left ventricle of the heart accelerates blood from rest to a velocity of +26 cm/s. (a) if the displacement of the blood during acceleration is +2.0 cm, determine its acceleration (in cm/s^2). (b) How much time does blood take to reach its final velocity Homework...

Homework Statement A ball is launched vertically upward from ground level with initial speed of 20 m/s. 1. How long is the ball in air? 2. What is the greatest height reached by the ball. 3. How many seconds after launch is the ball 15m above the release point. (Air resistance is negligible)...

Homework Statement A batter hits a pop fly straight up. a) Is the acceleration of the ball on the way up different from its acceleration on the way down? (YES / NO) b) Is the acceleration of the ball at the top of its flight different from its acceleration just before it lands?Yes / No...

1D wave equation -- bizarre problem! I am trying to write a solver for a 1D wave equation in python, and I have run into a bizarre problem that I just can't find a way out of. I start with the wave equation, and then discretise it, to arrive at the following, phi(i,j+1) = deltat2/deltax2...

A sprinter running a 100 meter race starts at rest, accelerates at constant acceleration with magnitude A for 2 seconds, and then runs at constant speed until the end. a) Find the position (relative to the start position) and speed of the runner at the end of the 2 seconds in terms of A...

Hi there. Long time no see. I hope you're all well. Homework Statement An infinite 1D system has electron plane waves occupying states 0 <= E <= E_F. At time t=0, a potential step is introduced such that V=0 for x<0 and V=V' for x>0. What is the electron density when the system reaches...

Ok, so this example question is in my lecture notes: Homework Statement "For a 1-D quantum well, 5nm width, 2eV barrier height, calculate the number of energy levels in the well." Homework Equations So the equation given is a familiar one: E_n=\frac{n^2 \pi^2 \hbar^2}{2 m L^2}...

The physics of a 1D string with fixed end points is found here: http://www.uio.no/studier/emner/matnat/ifi/INF2340/v05/foiler/sim04.pdf Now imagine a string under tension T and of mass density rho confined to the surface of a cylinder of radius r. I posit that this string will act just as...

Homework Statement "Two non-interacting particles are placed in a one-dimensional harmonic oscillator potential. What are the degeneracies of the two lowest energy states of the system if the particles are a)identical spinless bosons b)identical spin-1/2 fermions? Homework Equations...

I am fairly new to QM and am learning many of the basics right now. We were just discussing conservation of operators (energy, momentum, etc) and I recalled a problem proposed in my textbook about a 1D particle in a box of length L. at a time t, the box suddenly expands to t=2L, in which time...

All are true false but need help on all of them thanks in advance 1)Knowing the position and velocity of a particle allows its future position to be predicted even if its acceleration is unknown. 2)Instaneous velocity is the derivative of the displacement time function. 3)If the...

My textbook simply states that "For a simple 1D walk with step size L: <x^2> = NL^2 So after N steps 99.7% of the particles will be closer then 3L sqrt(N) from the centre" How does it get from the first to the latter?

Hi all, I have studied the Landauer's formula from the book "Current at the Nanoscale", but a formula made me confused. In the general case, for a nanoscopic transport, the book gives the formula: http://img19.imageshack.us/img19/2986/33768834.jpg In the following paragragraph it is...