Method Definition and 1000 Threads

I am studying the scientific method and have come to the following conclusion. Since X -> Y does not imply X is true (or real), it is impossible for the scientific method (SM) to prove that anything is true. So like mathematics, the scientific method builds knowledge on axioms which cannot be...

Homework Statement y″ − 2y′ − 3y = t 3 e 5t cos(3t) ---equation 1 Yp = (At3 + Bt2 + Ct + D) e 5t cos(3t) + (Et3 + Ft2 + Gt + H) e 5t sin(3t) ---equation 2 Homework Equations If there is any term in common, then the entire complex of product that is the choice for Y must be multiplied by t...

Homework Statement Hi I have attached an image which shows OK and OM which are position vectors such that OK=k and OM =m R is the mid point of OK and S is a point on OM such that (vec) OS = 1/3 OM L is the midpoint of RM, using a vector method, prove RS is parallel to KL. Homework...

x = 2y - y2 x = y

Homework Statement :[/B] I was learning the use of standard forms in method of substitution in solving integration. My book has given this method for solving integrals of the type ##\int \frac{lx +m}{ax^2+bx+c} dx##: As an example, the book gives this one: Homework Equations :[/B] The...

Homework Statement Determine the Finite Difference Method stencil for approximating a second derivative u''(x) at a discrete set of nodes with maximum accuracy for stencil of sizes (0,4) (off-centered). My questions: I think I am able to answer the question I am just not sure about what is...

Homework Statement Use the shell method to find the volume of the solid generated by revolving the region bounded by the line y = x + 2 and the parabola y=x^2 about the x- axis. Homework Equations - The Attempt at a Solution 1) x = √ (y) 2) x= y -2 V = ∫ (2 π ) ( y ) ( √ (y) - y + 2 ) from 0...

Homework Statement The load is known. Just 2 reactions needed to describe all external forces. Homework Equations method of joings The Attempt at a Solution I'm working on a pretty simple truss for work and want to check some of the elements for buckling. The strange thing is I am not...

Homework Statement This is a homework problem for a numerical analysis class. Use the following theorem to find bounds for the number of iterations needed to achieve an approximation with accuracy 10^-5 to the solution of the equation given in part (a) lying in the intervals [-3,-2] and...

Homework Statement Homework Equations Volume of Sphere = 4/3 pi r^3 d = m/v The Attempt at a Solution my attempt is: r = 2 Vsphere = 32/3 pi cm^3 density of mercury = 13.53 g/ml d*v of sphere = 259.7grams 259.7 grams of sphere * (1/density of mercury) = 259.7g *( 1 ml / 13.53 g) = 19.2 ml...

Hi all, There is this question; Firstly, I am new to quantum mechanics and there are a lot of terms I am unfamiliar with. So there is this question that asks me to develop a method to reconstruct state and I have no clue how I should start with. Any help or steps to solve this type of...

I have a system of equations which I solved with Newtons method. Call Newtons method a function NM=f(K1,K2). K1 and K2 are input and a vector of x=x1,x2,x3,x4 is output. I have another function, SSR, the sum of square residuals. It looks like this : $$\sum...

Hello everyone! I'm trying to get a deeper understanding on how to determine those periodic orbits in the equal-mass three-body Newtonian gravitational problems. The most general idea I know is to confine the three bodies into a zero angular momentum space, which sounds vague to me. What is the...

A friend and I have reached a disagreement, and truly neither of us can come up with the math to prove one of us right or wrong. So I pose the question in here for someone to offer me a proof of which theory is correct. The question is about what is the proper way to calculate damage per...

Hey! :o We have \begin{equation*}A:=\begin{pmatrix}-5.7 & -61.1 & -32.9 \\ 0.8 & 11.9 & 7.1 \\ -1.1 & -11.8 & -7.2\end{pmatrix} \ \text{ and } \ z^{(0)}:=\begin{pmatrix}1\\ 1 \\ 1\end{pmatrix}\end{equation*} I want to approximate the biggest (in absolute value) eigenvalue of $A$ with the...

Homework Statement Use the diffence method to sum the series ##\sum_{n=2}^N\frac {2n-1}{2n^2(n-1)^2}## Homework Equations from the textbook by Riley i have ##S_N=\sum_{k=1}^m f(N-k+1)-\sum_{k=1}^m f(1-k)## The Attempt at a Solution I prefer to write it as ##S_N=\sum_{k=1}^m...

I am quite sure at least some members here have their own particular way to go about learning a new topic or concept. But, does anyone have any advice for self learning something that is completely new or different without the help from classmates or a teacher about? I am self learning math...

Homework Statement I have this equations of motion, I have this equations of motion for a schwarchild black hole, I wish to use the 4th order Runge-Kutta method to solve them for a body falling to the black hole from a distance r0 and with L = 0. My problem is I am struggling to apply this...

I have seen two main different methods for finding the gradient of a vector from various websites but I'm not sure which one I should use or if the two are equivalent... The first method involves multiplying the gradient vector (del) by the vector in question to form a matrix. I believe the...

Homework Statement Homework Equations Fourier and then V(output) = 4Vs/(n*3.14) * sin (nwt) where Vs is battery here it's 400V Current = V(output) / X(L). Here X is 2*3.14*100*0.2 The Attempt at a Solution I got V(output) = 4*400/3.14 = 509.55V This is fundamental Peak output voltage. So...

Hi colleagues, I need your help to figure out some subtle theory problmes I have about this topic. I was thinking about a system composed by a conductive sphere (not grounded) under the effect of a pont charge placed near the sphere. As I know we need two image charges to satisfy the boundary...

I have a system of equations, and one of them is this : ##\int(1-U(y))Dy - H*\int(U(y)-U(y)^2)dy=0## Can Newtons method work if I approximate this integral to be ##\sum_y(1-U(y))-H\sum(U(y)-U(y)^2)=0## y is a set integers in range ##[1,1000]## I have Newtons method working for this same system...

I previously made a derivation of Neumann potential. It can be found in the pdf file below. I originally made it in the ##dx## method. It involved equations like ##dm=I dS##. My maths teacher told that such an expression has no meaning, at least in elementary calculus. However I argued that my...

Homework Statement Based on your understanding of Avogadro's law. 1000 L steel storage tank contains 88.5 kg of methane gas, CH4. Calculate no. of moles. The Attempt at a Solution one method= no. of moles=mass/molar mass. no. of moles= 88500/16.04= 5517.4 moles.other method= 1 mol= 22.4 liter...

Hello, I am assigned to write a code using bisection method (aka binary search method) The equation is 10sin(x) - x^3 - N where N = 1,2,3,4,5,6,7 My code is from math import sin def neg(a, b): return a*b> 0 def bisectx(funcx, lowx, highx,n): assert not neg(funcx(lowx,n), funcx(highx,n))...

The Scientific Method says that if a theory disagrees with observations, it has been falsified (according to Karl Popper). String theory predicts that spacetime is 10-D, but it is observed to be 4-D. This is a wrong prediction by the theory. So string theory is falsified. String theorists then...

What methods other than Light Dependent Resistor incorporation are there to determine the 'bulb state'? I'm guessing it's going to include the use of another type of optoelectric component? Thanks

Is there a way to look at mass spectra and determine the method of ionization? I.e., whether it's electrospray, FAB, MALDI, etc.

Equation \varphi(x)=x+1-\int^{x}_0 \varphi(y)dy If I start from ##\varphi_0(x)=1## or ##\varphi_0(x)=x+1## I will get solution of this equation using Picard method in following way \varphi_1(x)=x+1-\int^{x}_0 \varphi_0(y)dy \varphi_2(x)=x+1-\int^{x}_0 \varphi_1(y)dy \varphi_3(x)=x+1-\int^{x}_0...

Homework Statement Use Forbenius' method to solve this DE: $$ 5x^2y''+xy'+(x^3-1)y=0$$ Homework Equations Seek power series solution in the form ##y=\sum _{n=0}^{\infty } a_n x^{n+r}##, ##a_0\neq0## The Attempt at a Solution Sub in the ansatz y, get $$ \sum _{n=0}^{\infty...

Homework Statement Homework EquationsThe Attempt at a Solution My initial thought was to set the two equations equal to each other but the resulting equation is linear which gives a constant for a Newton iteration. I thought about Taylor's theorem in 2-d but I'm not so sure about that as far...

Create a class DecimalN which holds decimal numbers using dynamic arrays. Implement a constructor DecimalN::DecimalN(char* decimal) so that it can be created like for example DecimalN number("23.5698"). Create two class functions (methods) that given the number n it shift the number n places...

Homework Statement Linear and quadratic elements differ because of the extra mid-nodes on quadratic elements. Quadratic elements can "bend", linear can't. How do you define the DOF of a element? (see at solution attempt)Homework Equations - The Attempt at a Solution For example: a linear...

Homework Statement So I have an equilateral triangle of side(s) = 3x10^-2 m Im trying to find the value of the distance from a point directly in the middle of the triangle, to the middle of one side. Homework EquationsThe Attempt at a Solution What I wanted to do was, cut the triangle in...

Homework Statement Using the method of images discuss the problem of a point charge q inside a hollow grounded conducting sphere of inner radius a.Find (a) the potential inside the sphere (b) induced surface-charge density (c) the magnitude and the direction of force acting on q is there any...

In reading the posts re:Rustum Roy and electrolysis on salt I wondered if that method would work on other molecules? Not thinking about energy in and out, just how that or other means to separate a molecule's atoms could solve some problems such as pollution? Also, use of the term 'burn'...

Consider the scenario where there are two parallel conducting pipes of radius R separated by a distance d, with pipe 1 at a potential of -V and pipe 2 at a potential +V. I have seen from many sources that there is a very easy method of images solution to the potential outside the pipes, given...

The pioneering work by G. Lehmann, M. Taut, please see the attached files or download from wiley On the Numerical Calculation of the Density of States and Related Properties, http://onlinelibrary.wiley.com/doi/10.1002/pssb.2220540211/abstract The question is how the middle line of Eq. (3.9)...

Homework Statement [/B] Homework Equations This problem was from a practice exam. I know what V1 and V2 should be but can't get my answer to match. V1 should be -3.214 V and V2 should be -12.214 V The Attempt at a Solution See attached picture for my work. [/B]

I was wondering how I could measure the rate constant k for chemiluminescence reaction of luminol (when oxidised by H2O2. I was told that I can use a lux meter that measures the intensity of light emitted, but I'm not so sure how this can be done since the equation calculating the rate constant...

Homework Statement 2. Homework Equations 3. The Attempt at a Solution [/B]- So with the (from what i interpret of the notes this is needed) the same boundary conditions when time is fixed, we can relate the 'fundamental problem'- the initial condition ##t=0## given by a delta...

Homework Statement Find a particular solution yp of the given equation: y''+y=sinx+xcosx Homework EquationsThe Attempt at a Solution 1) First I got the temporary yp: Asinx+Bcosx+(Cx+D)sinx+(Ex+F)cosx 2) Then I got the associated homogenous eq. check for to check for duplicates: C1cosx+C2sinx...

Homework Statement Q1. Lindsay is twice as old as she was 10 years ago. Kimberly is half as old as she will be in 10 years. Find Lindsay’s age now? Find Kimberly’s age now? Q2. In 8 years Tiffany will be 3 times as old as she is now. The number of years until Tiffany will be 6 times as...

I've been recently studying the correlated-k method of calculating the absorption of EM radiation when passing through a sample of given thickness. I'm not sure if anyone here has experience on the same subject, but in case there is I have some questions... Suppose I have a material sample that...

Hi! For my math investigation project, I was trying to predict the trajectory of an object in a projectile motion with significant air resistance by using the Euler's Method. But it seems like the differential equation involved there can easily be separated into different variables, and so it...

Homework Statement Three points are given with errors on y coordinates. (2.00,4.70±0.36); (4.00,6.8&±0.45); (5.00, 9.10±0.50) Using LSQ method, find the error on slope. Homework Equations σm = σy√(n/Δ), where σy = √(1/n-2(Σ(yk - y(xk))^2)) and Δ = nΣxk^2 - (Σxk)^2 The Attempt at a Solution I...

Homework Statement the calculation can be considerably simplified by using the so called method of images. In this method, the electric field and potential produced by the induced charge distributed on the sphere can be represented as an electric field and potential of a single point charge...

A couple of friends ##n = 1 \ldots N## of mine bet on the result of the next general election in Germany. We select the six most important political parties ##p = 1 \ldots 6##. For each party ##p## and each friend ##n## we have the forecast ##x_{pn}## and the official election result ##x_p##...

I am using panel- data for 30 countries over 25 years to estimate a regression model. Expenditure on cars is my dependent variable and then I use economic theory to find some explanatory variables. First, is 30 countries and 25 years an ok sample? Or should years > countries? Second, is it an...

Hi All I need to do an evaluation of a pilot plant heat exchanger that we have installed and see if it would be better suited than our current bigger installations. I was trying to calculate the effectiveness of the heat exchanger but I keep on getting 1 with the NTU method. Below is the...