Questions tagged [physics]
Questions related to the application of Mathematica to problems in physics.
0
votes
0answers
51 views
Plotting elliptical orbits using Verlet method
I'm looking to solve a 2 body system consisting of the Earth and a body of mass in orbit.
I'm using the Verlet method to numerically integrate Newton's equation of motion in order to plot an ...
2
votes
2answers
56 views
Finding the amplitude of function solved using ParametricNDSolve
I have been trying to find the peaks of a function I have plotted using ParametricNDSolve. I have to find these peaks to calculate the amplitude of all the various waves in the observed output. By ...
1
vote
1answer
82 views
Conditional evaluation: black hole cross section
I'm trying to calculate the collision cross section of black holes, more precisely, I want the critical impact parameter $b_{\text{crit}}$ for a given initial velocity $v$ such that, at this speed, ...
22
votes
1answer
1k views
Animating wave motion in water
Further to this question I found on MSE, I tried to replicate
from here
this is as far as I got:
...
11
votes
2answers
739 views
Solving “Resistance between two nodes on a grid” problem in Mathematica
In the context of resistor networks and finding the (equivalent) resistance between two arbitrary nodes, I am trying to learn how to write
a generic approach in Mathematica, generic as in an approach ...
1
vote
1answer
65 views
Solve Euler Lagrange equation of motion DSolve
I'm trying to find Euler Lagrange equation of motion.
then DSolve the equation for list of variable x1,x2,x3,x4
Here is my code:
...
-1
votes
1answer
145 views
Working with motion equations
I'm trying to solve some Lagrange differential equations of motion, where $L = T - U$. Also, how can I use the solution for each x1, x2, x3, ..., xn?
Here is my code:
...
2
votes
0answers
44 views
Symbolic perturbation expansion for quantum mechanics using Hellmann-Feynman derivaties
I am interested in some quantum mechanical perturbation expansion for energies. Actually I want to implement these terms $E_n^{(k)}$. As is stated below one can do that using CAS. I would be ...
0
votes
0answers
56 views
Calculating forces on a truss
I need to find certain forces of the truss shown above, and I am asked to calculate the forces with a matrix.
The given values are
...
1
vote
1answer
80 views
A program for finding the summation of an analytical expression
Consider the Baker-Hausdorff formula for two operators $A$ and $B$:
$$e^BA e^{-B} =A+[B,A]+\frac{1}{2!}[B,[B,A]]+\frac{1}{3!}[B,[B,[B,A]]]+....,$$
where $[A,B]=AB-BA$. In the case of my problem, $[B,...
0
votes
1answer
84 views
Creating a numerical table of values from an interpolating function resulting from NDSolve [closed]
I am trying to carry out point "Implementing Map" on this paper Interstellar wormholes however I am using my own equations not those given (only the same method).
Part 1
I am trying to create a ...
0
votes
0answers
77 views
Numerical integration: gravitational force
What I would like to accomplish is to numerically integrate the following equation:
$\nabla^{2}\Phi(r)=\rho(r)$,
to get $\nabla\Phi(r)$.
$r$ is the radial distance from the origin.
Suppressing the $...
0
votes
0answers
56 views
Heat conduction problem with boundary at $\infty$
This is a 1-D heat conduction problem for a circular rod with 5cm, $T(x,0)=0$, $T(\infty, t)=0$, left boundary is insulated.
I am trying to use the finite numerical method. My first question is how ...
2
votes
0answers
81 views
Using Image Transformation to create image sky view of what its like to be near black hole (Not a wormhole) [duplicate]
Question : I am trying to carry out point 3. "Implementing map" on page 13 in the paper Interstellar wormholes using my own equations not those in the paper. however am not 100% sure on how to go ...
2
votes
1answer
50 views
How do I draw an angular vector field containing a domain wall?
Intuitively, an angular vector field $\theta(x)$ such as the following would describe a domain wall between two vortices/strings of opposite winding number.
I would like to draw this on a computer ...
3
votes
2answers
115 views
Carnot cycle diagram
Note: I have adopted and modified code taken from Wolfram demonstration page.
I want to achieve something similar to the following figure:
I use the following code:
...
0
votes
0answers
23 views
FeynCalc example — muon decay — integration issue
I'm just starting out using Mathematica and I'm trying to work through one of the examples given for FeynCalc, specifically the muon decay: https://github.com/FeynCalc/feyncalc/blob/master/FeynCalc/...
-1
votes
2answers
38 views
a ListAnimate problem
Thanks to @AlexTrounev, I learned how to use ListAnimate, but I still get stuck using it. Before ListAnimate everything is correct. I just cannot successfully use ListAnimate to make the plot. I have ...
0
votes
1answer
52 views
0
votes
1answer
93 views
Animate particle's trajectory
Does anyone know how to animate the trajectory of a particle, but make sure before the particle reaching a certain spot, there's nothing. I mean I want to make an animation that look like https://en....
1
vote
1answer
77 views
Euler-Bernoulli beam equation
I'm trying to solve Euler-Bernoulli beam equation with simply supported edges.$\frac{\partial^2} {\partial x^2} [ E I \frac{\partial^2 w} {\partial x^2}] + \rho S \frac{\partial^2 w} {\partial t^2} = ...
0
votes
1answer
86 views
Integrating Hamiltonian equations using NDSolve
Would someone be able to integrate numerically the equations at the bottom of page 12 in the paper Interstellar Wormholes given some initial conditions of your choice.
Reading the first paragraph of ...
5
votes
1answer
243 views
Integrating Hamilton's equations for the Schwarzschild metric
Part 1
I am trying to integrate Hamiltons equations for the Schwarzschild geometry using NDSolve, these equations must all be integrated simultaneously and are nice ODE's.
A similar task is done in ...
0
votes
0answers
6 views
Using manipulate in the plot of a function that depens on a FindRoot function [duplicate]
I've the following two codes:
FindRoot[Abs[Uin*Sin[2*Pi*fin*T - (Pi/2)]] - 2*Ud == (Uin - 2*Ud)*
Exp[-T/(c*Rb)], {T, 1/(4*fin), 1/(2*fin)}]
And:
...
1
vote
0answers
55 views
Trying to compute the heat capacity for the 2D-Ising model
I'm trying compute the heat capacity $C_v$ out of my simulation for the 2D-Ising model which is given by
$C_v = \frac{\langle E^2 \rangle - \langle E \rangle^2}{T^2N^2}$ ($E$: Energy, $T$: ...
0
votes
0answers
32 views
How to simplify my integrand to make the function Integrate[] work?
To calculate a physical field, I need to integrate a complicated expression, with Sin and Cos and some 3/2 power. But when I run the Integrate function, it seems running forever. So what could I do to ...
1
vote
0answers
45 views
Abstract derivatives in Feyncalc
I have encountered several problems regarding the application of formal derivative operators in FeynCalc, using the built-in function FCPartialD,
Left/RightPartialD
Schematic description of my ...
1
vote
0answers
54 views
Integrating wavefunctions over a sphere
I am attempting to numerically solve the inner product of two particles and an electric dipole interaction potential. I am incredibly limited in my skills, and need to know how I can begin setting the ...
2
votes
0answers
51 views
Antiparticles in Feynrules Lagrangian
I am trying to implement a simple extension of the SM to Feynrules, generating the Lagrangian in a Mathematica notebook file. I am wondering about the following:
Is there a way to explicitly use the ...
0
votes
1answer
77 views
How to graph acceleration from an equation given a sample period?
I am unfamiliar with Mathematica and the necessary syntax to approach visualize acceleration over time. I would appreciate some assistance or reference to a starting point on how to go about solving ...
2
votes
1answer
159 views
Interpreting Mathematica code on black holes
I am trying to understand the code written down on page 7 of this document (code is in Mathematica) I understand pretty much all of the code on the previous page needed to setup the page 7 code (...
0
votes
0answers
75 views
Solving a differo-integral equation [duplicate]
I've the following equation for x(t):
$$x'(t)\cdot\text{a}+\text{b}\cdot\frac{x'(t)}{x(t)+\text{c}}+\frac{\partial}{\partial t}\left\{\int_0^tx(\tau)\cdot\mathcal{...
1
vote
1answer
97 views
Rotation in physics [closed]
I have a mathematica problem in theoretical physics:
There is a rotation axis $\vec{n}$ with $|\vec{n}|=1$. Each other vector $\vec{v}$ can be seperated in relation to $\vec{n}$ in a parallel part ...
3
votes
1answer
104 views
Using DSolve to solve an integral equation
I've the following integral (or DE) that I need to solve (for $x(t)$ and all the constants are known, real and positive):
$$k\cdot\theta\left(t-m\right)+(n-k)\cdot\theta\left(t-v\right)=$$
$$x(t)\...
1
vote
2answers
104 views
Validating a solution for a differential equation with DiracDelta
For the following differential equation
$\displaystyle-\frac{\partial ^2\phi2 (x)}{\partial x^2}+\lambda ~[\phi2 (x)]^3-\mu ^2~\phi2 (x)=\phi2(x)~\delta(x)$
...
2
votes
1answer
64 views
center of mass, total momentum
Has someone an idea how to solve the 1. question for ANY number of mass points and a clue to the 2. question?
center of mass system, momentum
0
votes
1answer
81 views
center of mass system, momentum
when I have systems with 3 mass points ($m_i, i=1,2,3$) to a time $t=t_0$ on positions $\vec r_i(t_0)$ and velocity $\vec v_i(t_0)$. How could a syntax look like to calculate
1) center of mass
2) ...
1
vote
0answers
55 views
Decay chain browser
This https://demonstrations.wolfram.com/IsotopeBrowser/ used to be an excellent tool to demonstrate decay chains to my students. Unfortunately it does not work under newer versions of mma. Can anybody ...
3
votes
2answers
118 views
Initial values of position (x) and speed (v) of a particle visualizing using Mathematica
$$\vec{F}(\vec{r})=-m\omega^2\begin{pmatrix}x\\4y\end{pmatrix}$$
I have the force $F$ shown above. How could I specify the initial values of position ($x$) and speed ($v$) in Mathematica using the <...
0
votes
1answer
73 views
trajectory of a thrown object [closed]
I have a equation of motion v(t), that is integrated (t=0) to x(t). This symbolizes a trajectory of a thrown object. I want to create compared Plots for x(t) with different values for beta. When I try ...
0
votes
1answer
81 views
Solving a difficult differential equation
I've the following DE, describing a physical phenomenon. And the prupose is to solve that DE using Mathematica
$$x(t)\cdot r+x'(t)\cdot l+a\cdot\ln\left(1+\frac{x(t)}{b}\right)=0\space\...
4
votes
3answers
125 views
Plotting an Equation Using ParametricNDSolve
I'm trying to plot the solution of a set of differential equations and see how the solution changes when the value of a certain variable de is changed. The equations have solutions to the values of de ...
0
votes
0answers
72 views
Potential with two variables [duplicate]
How would a procedure look like to calculate a potential$$
V(r)=-\int_0^r F(s) \,\mathrm{d} s
$$
with example data:
...
1
vote
2answers
200 views
Time-dependent Schrödinger equation and density plot
I'm interested in the density plot of the solution of a 1D time-dependent Schrödinger equation with a given potential. So I have:
...
3
votes
3answers
209 views
Work of a force field [closed]
I have a parameter curve in 3d:
r1[t_] := {Cos[2 Pi t], Sin[2 Pi t], t}
r2[t_] := {1, 0, t}
r3[t_] := {1 - 1/2 Sin[Pi t], 0, 1/2 - Cos[Pi t]}
with a vector field:...
0
votes
1answer
63 views
Finding the minimum points of a discrete trigonometric equation
Basically I'm trying to solve the equation
$$A\Big(\sin(\theta_a-\theta_{a+1}) + \sin(\theta_a-\theta_{a-1})\Big) + B\Big(n_a^z \sin(\theta_a) - n_a^x \cos(\theta_a)\Big) = 0$$
subjected to the ...
3
votes
1answer
104 views
Using ImageTransformation to implement relativistic aberration effect
****The desired effect should be images that look like something out of Star Wars like when you are boosting to high speeds in the Millennium Falcon.****
This problem was tackled by Daniel Weiskopf ...
4
votes
1answer
193 views
Solving the eigenvalue problem for a double well potential using a 1D particle in a box as a basis set
My first question is how would I go about getting the 1D particle in a box eigenfunctions using matrix techniques and how would I use the particle in a box eigenfunctions as a basis set for the ...
4
votes
1answer
266 views
Dynamic, nonlinear, damped Euler–Bernoulli beam equation
I would like to solve the 3 coupled PDEs describing a damped, nonlinear (i.e displacements in the $x$ direction along the beam need to be considered along with the $y$ displacements normally ...
0
votes
1answer
34 views
NSolve cannot work with MinValue?
I am trying to solve the following problem: find the smallest value of $b$ such that the inverse of the solution u[p] given by ...
