# Tagged Questions

Questions related to the application of Mathematica to problems in physics.

174 views

### My code uses ClebschGordan but Mathematica is using ThreeJSymbol

I'm using a function that calculate CG coefficients with the function ClebschGordan but instead, I've got the following error because Mathematica is using ...
114 views

### Solving 2D Laplace equation for irregular boundaries [on hold]

I want to solve Laplace equation in 2D with $x$ and $y$ coordinates with the boundary conditions $V(0,y)=-180$; $V(x,0)=50x-180$; $V(x,6)=50x-180$; $V(453.595-\sqrt{450.05^2 - (y - 3)^2},y)=0$ The ...
100 views

### Ballistic motion of a particle giving trouble at high drag values

The following code: ...
791 views

### draw part of parabola using graphics

today I was doing my physics homework. one of the questions was draw velocity-time and position-time graphs from the acceleration-time graph. So for the first step I draw acceleration-time using ...
92 views

### Animating ballistic movement

I was tasked with creating a 3D animation of the movement of a ball through space, while taking into account influences such as the magnus effect, air drag, and rotation. In order for this to happen a ...
266 views

### Heat convection differential equations from 1952 - Mathematica “fails to converge”

I am trying to solve a fundamental problem in analytical convective heat transfer: laminar free convection flow and heat transfer from a flat plate parallel to the direction of the generating body ...
115 views

### How to numerically solve a 1D time-independent Schrödinger equation for two interacting particles

Solving the 1D single-electron time-independent SchrÃ¶dinger equation has been demonstrated using NDEigensystem here. There, the single-electron SchrÃ¶dinger equation ...
259 views

### Ion motion in uniform axial magnetic field and radial electric field [closed]

I'm trying to model an ion's 3D motion in a constant/uniform axial magnetic field and a radial electric field (similar to a cylindrical magnetron, but two positive parallel center electrodes offset by ...
153 views

### Controlling scaling of multiple vector fields in VectorPlot3D

I'm trying to plot the electric and magnetic fields of a relativistically moving electric charge using VectorPlot3D, and apply "Manipulate" to change the velocity. The code I'm using is as follows: <...
103 views

### Calculating density of states from lists of momentum/energy data

I am trying to calculate the density of states for a 2D system given certain band structure data organized in a specific format. Below is an example of my procedure: Beginning with a simple 2 x 2 ...
2k views

### How to create an inverse pole figure color map

To interpret electron backscatter diffraction (EBSD) results, inverse pole figures are used. A three dimensional space of directions ([100], [110] and [111] for those who know about crystallography) ...
119 views

### How? 2-dimension visualisation of all 3d-orbitals as either a density plot or as function of maximal radius

I've been playing around with some d-orbitals and have been trying to view their maximum in two dimensions. At the moment I've progressed to the point where the d__ orbitals are superimposed onto one ...
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### Lagrangian for Spring-Pendulum [closed]

I solved a Spring-Pendulum System with NDSolve. I tried to plot a graph with the interpolated data but always returns a message "An improperly formatted directive with head Symbol was encountered." <...
3k views

### Convert spectral distribution to RGB color

Presume that I have a spectrum as a function of wavelength (an example being the blackbody spectrum): I want to convert that to a single RGB color to display on-screen, i.e. the "color" of that ...
325 views

### Lagrangian to Hamiltonian

I want to go from Lagrangian description to Hamiltonian one. Using the example given by Mathematica I do something like: ...
975 views

### A better “VisibleSpectrum” function?

Since ColorData["VisibleSpectrum"] is wrong, I would like to have a more accurate function to use. Can this information be extracted from Mathematica itself?
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### Solving Time-Dependent PDE's Analytically with no non-trivial Boundary Conditions

I'm having some trouble solving a partial differential equation that is supposed to model the propagation of a scalar field in Schwarzschild spacetime using spherical coordinates. I'm using the DSolve ...
38 views

### Recycle boundary condition

I'm having the following issue that can not find a solution , by using this boundary condition u[0, t] == 2 u[1, t] that Mathematica does not understand, someone ...
84 views

### Jump boundary conditions

I'm having the following issue that can not find a solution , by using this boundary condition ...
88 views

### Free-fall air resistance problem

IÂ´m working on a free fall problem and I got an equation with variable $k$ when the situation has air resistance. Then I compared with no air resistance equation ($-4.9$, considering t variable). So, ...
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### Solve returns empty list on system of 62 linear equations with undeclared known variables

Context: I am trying to solve a set of equations generated by hand from a complicated, but not particularly strange system via Newton's Second and Third Laws, and a few constraints. All the resulting ...
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### Verify angle pi/4 maximizes launch range [closed]

I'm solving the equation of motion for a projectile in the x, y plane and got this: R = v0^2 sin(2 theta) / g where R is the range of how far the object will ...
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### Plotting graphical analysis of chaotic behavior

I am trying to plot some results of chaotic behavior in a system based on a paper for one of my classes. I am a physics undergrad. I found some sample code online springy.nb which I have been trying ...
173 views

### Can I convert a 3-D plot into a 2-D plot?

I am studying the Landau Free Energy Equation. First of all the plot displayed only shown negative range. can i show the positive range too? (y-axes). Then, can I turn this plot into 2-D Plot? ...
57 views

### NDSolve and vectors [closed]

I think I can't find solution of equation below because I need use scalars, not vectors as I have tried. But I don't know how I can do express the problem with scalars. I have read Wolfram Language ...
288 views

### How to model wooden joints with mathematica's FEM?

This is a dovetail joint: and I'd like to see the stresses and deformation on the joint.I haven't seen any modeling of disconnected regions with FEM, only connected regions, so I'm curious if you ...
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### Sampling a phase space uniformly for a given energy?

The energy for a 1D harmonic oscillator can be written: $$E = \frac{1}{2 m} p^2 + \frac{m \omega^2}{2} x^2$$ where x is position and p is the momentum. I would like to sample phase space $(x,p)$ ...
102 views

### How to find the eigenvalues of a custom operator using NDEigensystem? [closed]

I would like to solve a Hamiltonian presented by a 2x2 matrix. Hamiltonian is given by: ...
125 views

### Animate spherical pendulum

I want to plot the position of Spherical pendulum. First I tried to plot the simple pendulum: ...
124 views

### How can I solve a Hamiltonian with numerical methods?

Hamiltonian in terms of two level atom's operator (0 is ground state and 1 is excited state) which are 2*2 matrices and cavity modes are given by $a$ and $a^\dagger$. Rest of the parameters are ...
80 views

### Determine the initial speed and launch angle of a projectile from its trajectory

I have the coordinates {x,y} needed to plot the trajectory of a projectile, which are given below: ...
238 views

### Problems with NDSolve for solving coupled Schrödinger-like PDEs with perfectly matched layer boundary condition

I'm trying to solve a full-vectorial wave equation for an arbitrarily shaped wave guide, by using NDSolve and perfectly matched layer (PML) conditions. The PML ...
121 views

### Improving the speed of evaluating numerical solution to a sytem of PDE

I am running a simulation for a kinetic reaction inside a pellet modeled by a system fo reaction-diffusion equations. ...
148 views

### Beam deformation due to localized force distribution

I would like to simulate the deformation of a beam which is fixed on one end and has some localized forces applied along the top. I have been inspired by this Mathematica example: http://www....
675 views

### Calculate inertia tensors

Moments of inertia and inertia tensors are well-known characteristics of rigid bodies in physics and applied mathematics. How to calculate them in Mathematica? Is possible to use regions which was ...
3k views

### The Orbit and Perigee of the Flamsteed comet

Historical context This year we have the 330-th anniversary of the Battle of Vienna - one of the great formative events of European history, it took place on September 12, 1683. Kara Mustafa, Grand ...
272 views

### How to see phase difference of two pendulum

i want to see the simulation of two uncoupled Simple Harmonic Motion (SHM) pendulum with different Lengths and released at different initial displacement angles. in this case adding one more pendulum ...
89 views

### How to make A simulation of 2-Dimensional Projectiles

Lets say two cannon is fired at different initial position, initial angle and initial speed. let say initial speed,angle and position for projectile 1= ...
77 views

### Making a Manipulate showing a the motion of a particle [closed]

Solving a differential equation I got to the following result -(((R[n*Pi - t/w] Cos[t/w])/(n*Pi)) Then, using this solution, I create . ...
161 views

### Boundary Problems

I am trying to study what happens to a wave as it passes different boundaries. This is the working wave equation defined on a plane ...