Method Definition and 1000 Threads

Ratio of moment of inertia of a circle and that of a square having same area about their centroidal axis is: Sol: both area and square have same area: ##a^2 = \large\frac{π}{4}\normalsize d^{2}; \large\frac{d}{a} =\large \sqrt\frac{4}{p}## Ratio of moment of inertia of a circle and that of a...

As part of my project I was asked to use the finite difference method to solve Schrodinger equation. I see how you can turn it into a matrix equation, but I don't know how to solve it if the energy eigenvalues are unknown. Are there any recommended methods I can use to determine those...

c^2=a^2+b^2-2abcosC°1/2 = 32^2 =38^2 - 2(32)(38)cos35(0.5) = 2468-995.904 = √1472.096 = 38.36 N tanΘ= 32/38 tan= 0.842 = 40° This is my attempt, I am not sure that I am understanding these formula right

If it is the asymptotic behavior of the Airy's function what it's used instead of the function itself: Does it mean that the wkb method is only valid for potentials where the regions where ##E<V## and ##E>V## are "wide"?

In fact I'm working on a condensed matter physics paper, where I stumbled with an integral that I need to visualize. The function, Ls I need to visualize is equal to: $$Ls=4\nu^4 \dfrac{\int_{-1}^{1} \dfrac{( 1-u^2)}{(u+\sqrt{u^2-\nu^2})^3} \, du}{\int_{-1}^{1}-u \Big...

Hey! :o I am looking at the following: Use the Quine-McCluskey method to determine the respective prime implicants for the following boolean functions and find a disjunctive minimal form. If available, also give all others disjunctive minimal forms. \begin{equation*}f(x_1, x_2, x_3...

I have written some ODE solvers, using a method which may not be well known to many. This is my attempt to explain my implementation of the method as simply as possible, but I would appreciate review and corrections. At various points the text mentions Taylor Series recurrences, which I only...

In teaching HS Physics part of which is Electric Circuits, I have discovered a rule / technique for parallel resistors that I never encountered in all my 30+ years in electronics engineering, nor in any textbook on Circuits. It is what I call " The N + 1 Rule " We all know the Reciprocal...

Hello, I posted the same in the partial differential equations section but I'm not getting responses and maybe this section is better for help with homework. I have to solve this problem: $$u_t=ku_{xx}+h \; \;\; \; \; 0<x<1 \; \; \,\; t>0$$ $$u(x,0)=u_0(1-\cos{\pi x}) \; \;\; \; \; 0\leq x \leq...

Hello, Can you please help me to solve this exercise: Let f a function that satisfies: - f is class C2 and strictly convex (f'' (x) > 0). - There is x*, f' (x*) = 0. Question is: prove that the minimum of f is reached in x* and it's unique? Using the descent gradient method (build a sequence...

Hello, I have to solve this problem: $$u_t=ku_{xx}+h \; \;\; \; \; 0<x<1 \; \; \,\; t>0$$ $$u(x,0)=u_0(1-\cos{\pi x}) \; \;\; \; \; 0\leq x \leq 1$$ $$u(0,t)=0 \; \;\; \; \; u(1,t)=2u_0 \; \;\; \; \; t\geq0$$ So I know that I can split the solution in two (I don't know the reason. I would...

See Reference: ArXiv: 1208.0644 The Bargmann Wigner Method seems to be a means to obtain wave equations for higher spins, I.e. j=1, 3/2, 2, etc. In this method, one uses a Dirac-like equation to operate on a wave function. For example, equations, 2.2 and 2.3 show Dirac-like equations that...

I attempted the solution using force method. I got correct. However, I was stuck at the alternative way to solve problem using energy method. As shown in screenshot 2, he tells that the energy of system changes due to 2 ways: - The tension T - Leaking of mass As shown in screenshot 2 ,the...

I'm supposed to calculate the current and the phase angle. Can someone please tell me if this is the correct solution?

For Initial Value problems I want to implement an ODE solver for implicit Euler method with adaptive time step and use step doubling to estimate error. I have found some reading stuff about adaptive time step and error estimation using step doubling but those are mostly related to RK methods. I...

Simplex method

Mentor note: Thread moved to Diff. Equations subforum Hello, few days ago I had a calculus test in which I had to find the general solution for the next differential equation: (D^8 - 2D^4 + D)y = 0. "D" stands for the differential "Dy/Dx". However I could only find 2 of the roots on the...

The digital CT (current transformer) operated energy meters are tested in field using consumer's load conditions by means of a parallel test equipment. It was observed that the reactive energy measurement has high accuracy mismatches on harmonic polluted loads. Some literature indicates that...

Hello, can anyone tell me why do we take 4,5 and 5,13 instead of 4,6 and 13,15?Thats QM method

Its been awhile since I even thought about conducting a scientific experiment, and I do remember that you need a dependent variable.. the observation or effect such as the apple fell from the tree, and then the independent variable, such as gravity. But in order to test the hypothesis, you...

I've been studying C# programming, and I came across the following method for calculating factorials that I find confusing. It looks like, in the body associated with "else," the method calls on itself. As a guy with a lot of Fortran coding experience, I've never seen anything like this. I...

Homework Statement Show using your expression for \lambda that if at a time t1 the amount is y1, then at a time t1 + ##\lambda## the amount will be ##\frac{y1}{2}##, no matter what t1 is.Homework Equations y = y0 ##e^{kt}## From previous question: half life ##\lambda =-ln2/k## The Attempt at...

Hi, it may look like a homework but believe me that it's not. Castigliano's method was omitted when I was attending mechanics of materials course at my university and now I'm catching up. Another reason why I want to solve this is that I'm just curious what's the formula for the deflection of...

Homework Statement Hi, I am new to MATLAB and have an assignment where I have to construct a Hamiltonian matrix, apply boundary conditions, then find corresponding eigenvalues and eigenvectors for the electron in a box problem. I am stumped where to start. From our class we learned that you...

Homework Statement Homework Equations The Attempt at a Solution I'm sure my solution is wrong because of Φ(z=0) ≠ 0 I searched the internet for a similar problem but I couldn't. Any help will be appreciated.

Homework Statement The diagram shows parallelogram ABCD. (you don't really need the diagram) vector AB= (2 above, 7 below) and vector AC= (10 above, 11 below) The point B has coordinates (5, 8) (a) Work out the coordinates of the point C. The point E has coordinates (63, 211) (b) Use a...

The problem says: A radio station emits electromagnetic wave with a frequency of 100MHz (102*106 Hz). a)What's the energy of this radiation's/glow's photon? (Solved, i found 6,63*10-26 J) b)Compare your calculation with the energy of another visible radiation/glow, with a wavelength of 600nm...

Homework Statement For the given circuit (see below), find the voltage across resistor 3. Homework Equations n-1 Kirchhoff's Current Laws for n nodes. The Attempt at a Solution Can anyone verify whether my KCL equations are correct? The mixture of source voltages with node voltages may...

Hey! :o I want to determine an approximation of a cubic polynomial that has at the points $$x_0=-2, \ x_1=-1, \ x_2=0 , \ x_3=3, \ x_4=3.5$$ the values $$y_0=-33, \ y_1=-20, \ y_2=-20.1, \ y_3=-4.3 , \ y_4=32.5$$ using the least squares method. So we are looking for a cubic polynomial $p(x)$...

Hello everyone, I'm aiming to produce a lightweight steam engine, which will essentially have a coil of copper tube inside the walls of a tube made of >your suggestions here<. this tube is the exhaust for a blowtorch. The principle is that this tube gets very hot, then transfers heat to the...

I have equation system: x + y + z - a*k = 0 -b*x + y + z = 0 -c*y + z = 0 -d*x + y = 0 where: a, b, c, d = const. Have to find: x, y, z, k Attempt of solution: I create Matrix A with coefficients; Matrix B - Solutions (Zeros) and Matrix X - variables. When I try to use Cramer's rule -...

Hey! :o We have the following two versions of Gram Schmidt orthogonalization method: Show that both algorithms are mathematically equivalent, i.e. $s_{ji}=r_{ji}$ for all $j\leq i$ and $\tilde{q}_i=q_i, i=1, \ldots , n$ for the output vectors. I have done the following: The difference...

Homework Statement how do we solve the ode ## y'+y^2=-2, y(0)=0## using adomian decomposition method?Homework EquationsThe Attempt at a Solution ##Ly = -2-y^2## ## y= 0 + L^{-1}[-2-y^2]## ##y_{0}= -2t## ##y_{1}= -L^{-1}[4t^2] = -4t^3/3## are my steps correct so far in trying to get the Adomian...

Hi All, The free Windows command-line untilities Netstat and Netstat -an alllow one to view all ports, connections used when surfing the web. Still, is there a way to _close_ any connection. I am interested in doing it within SQL Server, but I wonder if there is a more general way of doing it...

Homework Statement I have the circuit given below with a single node where R3 and ground meet. How can I solve this problem using the inspection method? Is it possible? I can easily solve using another method but I would rather try using the inspection method. Homework Equations Ax = M A is...

Hi! I have a code that solve the poisson equation for FEM in temperature problems. I tested the code for temperature problems and it works! Now i have to solve an Electrostatic problem. There is the mesh of my problem (img 01). At the left side of the mesh we have V=0 (potencial). There is a...

[FONT=Helvetica]Use Euler’s Method with a step size of [FONT=Helvetica][FONT=MJXc-TeX-math-I]h[FONT=MJXc-TeX-main-R]=[FONT=MJXc-TeX-main-R]0.1h=0.1[FONT=Helvetica] to find approximate values of the solution at [FONT=Helvetica][FONT=MJXc-TeX-math-I]tt[FONT=Helvetica] = 0.1, 0.2, 0.3, 0.4, and...

Homework Statement i have been trying to learn bessel function for some time now but to not much help firstly, i don't even understand why frobenius method works why does adding a factor of x^r help to fix the singularity problem. i saw answers on google like as not all function can be...

$\tiny{2.7.2}$ 1000 (a) Find approximate values of the solution of the given initial value problem\\ at $t = 0.1, 0.2, 0.3$, and $0.4$ using the Euler method with $h = 0.1$.(b) Repeat part (a) with h = 0.05. Compare the results with those found in (a).(c) Repeat part (a) with h = 0.025. Compare...

I saw this video for testing whether one has graphene or graphite and was wondering about the authenticity of the method. By mixing 50%h2o and 50%gasoline the graphene should separate/settle in between the two within a second after shaking. Here are some pictures of my own experiment before...

Homework Statement Problem: a continuous beam ABC simply presses, loaded with a distributed load q, the length of the beam is 2L. EI=constant find the reactions in the beam ,we use Castigiliano method. Homework Equations - U=(1/2EI)∫M^2 dx (U: Energy) - dU/dP=d (d: displacement) The...

Hello everyone, this is my first post here so please excuse me if its in the wrong area. I am looking for the tabular approach to solve a complex gear train based off the spur gear differential design. Attached is a photo of the differential. The requirements of the necessary differential...

Hi. I am practising for my test and since I don't have the correct answers, I don't know if what I'm doing is right. I tried to solve this problem, can you check it and correct if it's wrong? Here's a clearer picture of the circuit. I suspect Uab isn't right, but am not sure. Thanks...

In ##c=1## units, from my SR courses I was told for example, that the Minkowski metric ## ds^2 = -dt^2 + dx^2 + dy^2 + dz^2 ## can be written in matrix form as the below.. \eta = \begin{pmatrix} -1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \end{pmatrix} And it was just...

Homework Statement I need to solve the DE y’ = x^2y using the power series method Homework Equations y = sum(0->inf)Cnx^n y’ = sum(1->inf)nCnx^(n-1) The Attempt at a Solution I plug in the previous two equations into the DE. What is the general procedure for these problems after that...

Homework Statement Hello, using Simpson´s method, one can calculate the number of intervals needed to achieve a given accuracy, through the error formula. Is there any other way to know that the required accuracy is achieved other than computing the integral and comparing it to the result from...

Homework Statement see attached, question 8a and b are what I'm attempting. I've also attached the VERY brief course notes that I'm required to work with. I know Tc= 8 seconds from the graph (0.13minutes) Gain set to 4. is PB therefore 100/4=25%? I'm struggling to calculate the ratio of...

1. y' + y = x y2/32. The problem states we need to solve this ODE by using the method of integrating factors. Every example I found on the internet involving this method was of the form: y' + Py = Q Where P and Q are functions of x only. In the problem I was given however, Q is a function of...