Method Definition and 1000 Threads

Hello! (Wave) I want to check if the method of separation of variables can be used for the replacement of the following given partial differential equations from a pair of ordinary differential equations. If so, I want to find the equations.- $[p(x) u_x]_x-r(x) u_{tt}=0$ - $u_{xx}+(x+y)...

I had this setup (see attached photo) for the linear gate method in a γγ coincidence experiment. Using a Na22 source. The pulse from the movable detector enables the gate of the MCB, and any corresponding pulse from the fixed detector that arrives within the gate interval will be considered...

$\tiny{17.2.01}\\$ $\textrm{ Solve the given equation by the method of undetermined coefficients.}$ \begin{align*}\displaystyle y''+7y'+10y&=80 \end{align*} $\textit{this is in the form}$ \begin{align*}\displaystyle x^2+7x+10&=0\\ (x+2)(x+5)&=0 \end{align*} $\textit{this is a...

Homework Statement (Picture attached) Question 1: The system starts at rest. Block a accelerates towards the bottom the the rod. Find the velocity of the block when it is at the bottom of the rod using the "vector method". So this was my midterm question today. I knew how to figure out how...

Hello. How do I solve this equation without killing the k(y) term: I managed to derive an analytical solution for this one. I intend to run the numerical solution via Runge-Kutta but I can't stop myself from killing the k(y) term. I'm starting to think I'm doing something wrong... It goes...

So if I have a logistic regression: ##log (\hat {odds})=\hat{\beta_{0}}+\hat{\beta_{1}}x##. How would I find a confidence interval for x if I am given ##odds=5## This is going in reverse, where if I have the outcome, I try to do inference on the predictor. We know that ##\hat{\vec{\beta}}##...

I'm working on a question which asks to determine the deflection, curvature, forces and moments of a simply supported beam with a distributed load. diagram shown in here http://imgur.com/a/wpI4kInitially, I've done the calculation with 1 plane beam element with 2 nodes. At L = 0 and L = 3. But...

Question on SIR Model and using Eulers method for approximating a solution. Given the 3 ODEs of the SIR model dS/dt = -\betaSI dI/dt= -\betaSI - \gammaI dR/dt = \gammaI Ive been asked to produce in excel Eulers method for axproximate solutions. Given some initial values for S(0) and I(0) as...

Homework Statement two semi infinite grounded conducting planes make a 60 degree angle. One plane along the positive x-axis. There is a charge Q at point (m,n) located closer to the plate running along the x-axis than the other. what would a diagram look like with all image charges and angles...

Homework Statement What collection of image charges solves the problem in above pictured ?? Homework EquationsThe Attempt at a Solution One of the image charge should be in dielectric region q'=-((e2-e1)/(e2+e1))

I have to study art, history and philosophy in order to pass the year and get to the university, I am doing really really bad at them and when i study them i get always distracted because i hate them a lot... How can i do? The idea that i I'm in trouble doesn't make any effect on me, seems like...

I have a very fundamental question about the linear variational method (Huckel theory). It says in any textbook that the variational method provides energy upper bound to the actual energy of a wavefunction by using test wavefunction. \varepsilon = \frac{\sum_{i,j}^{n}C_{i}C_{j}H_{ij}...

Homework Statement Okay, this one is a bit big, and I'm attempting a translation, so I'm going to post a TL;DR version at the bottom just to be sure. Anyway, here goes: While doing an experiment, we write down the values of a physical/natural size y, for various values of a physical/natural...

hi, i know a little bit of ODE but not much about PDE,Some math programs give me the solution but I would like to know what methods they use. The problem is the following: $$I(a,b) = \int_{0}^{\infty} e^{-ax^{2}-\frac{b}{x^2}}$$ through differentiation under the integral sign, substitution...

Homework Statement I am asked to find the member force of AB and DE Homework EquationsThe Attempt at a Solution I make an imaginary cut of the question and consider the upper part of the cut . Bur , i didnt get the same ans provided . However , when i consider the lower section of the cut , i...

Just a basic question. It's as the title says, If I'd want to determine the latent of oils (or any material for that matter), is the same methodology used for determining the L.H. of ice applicable? (e.g...

The Genkin-Mednis is usually used to calculate the nonlinear optical properties of periodic polymers or crystals, the analytical derivation is captured in the posted image, My problem is (483), where does an extra term on the right hand side of (483) come from? ie S^\dagger (\kappa...

Can someone explain to me why that highlighted force is 0? Homework Equations ∑Fx = 0 The Attempt at a Solution I found FDC to be 780lb and I am still trying to solve for FDE

Homework Statement For moment about D , how could the FGF sin26.6 generate moment about D ? Homework EquationsThe Attempt at a Solution FGF sin26.6 is located above point D , right ? How could FGF sin26.6 generate moment about D ?

Homework Statement Using Sturm-Liouville theory, estimate the lowest eigenvalue ##\lambda_0## of... \frac{d^2y}{dx^2}+\lambda xy = 0 With the boundary conditions, ##y(0)=y(\pi)=0## And explain why your estimate but be strictly greater than ##\lambda_0##Homework Equations ##\frac{d}{dx} \left...

Homework Statement $$\frac{\partial u}{\partial t} + x^2 + t+\left(\frac{\partial u}{\partial x}\right)^2 = 0\\ u(x,0)=0$$ Homework Equations $$ \dot{x} = 2 u_x ;\,\,t=0,\,\,x=\xi\\ \dot{u}=2(u_x)^2+u_t ;\,\,t=0,\,\,u=0\\ \dot{u_x}=-2x ;\,\,t=0,\,\,p=0\\...

is= 1.2 mA i submitted my solution but it was wrong,can someone please explain why? /* i just wanted to check if my solution is correct so i don't lose marks on my homework did i do any mistakes ? if so please explain.*/ my solution:

Hi, I have two degrees. A BA in physics and a master's in computer science. I've taken more than 30 hours in upper level biology courses and a decent number of hours in mid level chemistry. One thing that I can attest to is that all of the disciplines have a different feel to their respective...

Hello! I'm starting a project with one of my professors at college whose subject is the Boundary Element Method. I've studied a little bit of Finite Element Method, but BEM is new to me. This project will envolve a lot of programming in Python and Matlab. I would like to know how does BEM...

Hi, Physics forum! Just a little push of my doubts I hope somebody could help me with my confusion of one of our home works. I know that all boundary conditions are zero. My doubt is how do I interpret (x,y,0)=0.01 source in the figure? Where is it located in the grid. I am hoping someone...

Hello! I am trying to write a program that solves the Schrodinger Equation for a particle in an infinite square well. I did a lot of research regarding the methods that could be used to accomplish this. I am writing this program in Matlab. The method I am using is called the Shooting Method. In...

Homework Statement Due to formatting problems, I have attached the problem below. Homework EquationsThe Attempt at a Solution Plotting the appropriate graphs and based on linearity, I have determined that the reaction is first order with respect to [O2] and second order with respect to [NO]...

1) the problem I understand Newton's method and I was able to find all the real roots of the function.However, I don't understand how to find the complex roots. I know that z=x+yi, and that I can plug in z for the formula. However I, don't know how to change the function (...

Anybody know how calculate the noise with equipartition theorem method? For a simple RC one order filter. The noise charge across the capacitor is Q. we have 1/2*k*T=1/2*C*(Q/C)^2 For a more complicated network as below. Can you help me on how to calculate the total noise charge or voltage...

$\textsf{1) Evaluate the integral}$ \begin{align*} I_1&=\int x \csc^2 6x \, dx\\ u&=6x\therefore du=dx\\ dv&=\csc^2(6x) \, dx \therefore v=-\frac{1}{6}\cot(6x) \\ u&=6x\therefore du=6 \, dx \\ I&=-\frac{1}{6} x\cot(6x)+\frac{1}{36}\int \cot(u) \, dx\\ &=\color{red}{ -\frac{1}{6} x\cot(6x)...

Homework Statement Upon using Thomas young’s double slit experiment to obtain measurements, the following data were obtain. Use these data to determine the wavelength of light being used to create the interference pattern. Do this in three different ways (6) • the angle to the eighth maximum...

Homework Statement Two boxes with masses m_1 = 4 kg and m_2 = 10 kg are attached by a massless cord passing over a frictionless pulley as shown in in my picture. The incline is frictionless and thetha = 30 degrees Homework Equations f = ma The Attempt at a Solution [/B] Tension 1 is...

Is there a way to estimate the upper limit and lower limit of time for doing a work? Suppose we are learning a page of facts and want to estimate the upper and lower limit of time taken to do so. If we start estimating the time we will find that the pages are learned in some variable periods of...

Homework Statement Use the shell method to set up and evaluate the integral that gives the volume of the solid generated by revolving the plane region about the x-axis. $$y=\frac 1 x$$ Homework Equations $$Volume=2\pi\int_a^b p(y)h(y)dy$$ The Attempt at a Solution [/B] I see that there...

$\tiny{242t.9.1.15}$ $\textsf{Use Euler's method to calculate the first three approximations}$ $\textsf{to the given initial value problem for the specified increment size.}$ $\textsf{Calculate the exact solution. Round to 4 decimal places.}$ \begin{align*}\displaystyle...

Dear all I want to loading about 14 ton of CMS (Carbon Molecular Sieve) into a PSA Nitrogen Producer tank. The tank is 5 meter tall with 2 m in diameter. What is the best, simplest and fastest method to load the pellet of CMS into that big tank? I consider this mortar screw pump and connect it...

$\tiny{9.1.14}$ $\textsf{Use Euler's method to calculate the first 3 approximations to the given initial value problem for the specified increment size.}\\$ $\textsf{ Calculate the exact solution.}$ $y'=y^2(5+5x), y(1)=-1, dx=0.2$ $y_1=$ $y_1=0.4$ $y_2=0.6268$ $y_3=1.2694$...

Homework Statement Using the circled formula , here's what i gt (photo3) , , why the author ignore the blue circled part ? Is the author wrong ... If the blue part isn't ignored , i gt this pls refer to the photo 3 which is correct ? The author or me ? Or I'm misunderstanding something ...

The standard method for hydrazine analysis published by the National Institute of Occupational Safety and Health (NIOSH) presented a methodology I found a little bit confusing. The first four steps of the procedure are as follows: SAMPLING: 1. Connect the outlet of the sampler and the inlet of...

Hi guys, Just looking for some help with the theory on a project I've been set at university. The experiment involved heating a long thin bar from one end with a sinusoidal heat wave. Thermocouples were then placed every 7 cm (4 in total) and temperatures were recorded. The experiment brief...

Hi, The problem is to solve: dy/dx = −[2x + ln(y)]*(y/x) Attempt: I have tried to see if it is exact, I found it not to be, I can't easily find a function to multiply by to make it exact either (unless I am missing something obvious). It clearly isn't seperable, nor is it homogenous (I know...

Homework Statement A particle P is performing simple harmonic motion with amplitude 0.25m. During each complete oscillation, P moves with a speed that is less than or equal to half of its maximum speed for 4/3 seconds. Find the angular frequency of P The Attempt at a Solution First I split 4/3...

Hello! (Wave)I am reading about the Method of Four Russians from here. We divide the dynamic programming table $D$ into $t$-blocks such that the last row of a $t$ − block is shared with the first row of the $t$ − block below it (if any), and the last column of a $t$ − block is shared with the...

Homework Statement I don't understand why the stiffness for span have extension pin stated from original stiffness ... According to online notes , for the far end pin / roller , the k is 3EI / L but not 3EI / 4L , is the notes wrong ? And i don't understand what is AA' beam , can someone...

Hello! Can someone explain to me how the double blind method is used in particle physics (especially in LHC)? Thank you!

Homework Statement I don't understand why the stiffness for span have extension pin stated from original stiffness ... Homework EquationsThe Attempt at a Solution According to online notes , for the far end pin / roller , the k is 3EI / L but not 3EI ***/ 4*** , is the notes wrong ?

Is there a book about how to do research in Physics or Physicist's experience? especially in Astrophysics, if not, general physics is also very good. thanks.

Homework Statement In the first photo , interval [-2 ,2 ] means a = -2 , b = 2 , am i right ? So , how to show that b-a = 1 ? Homework EquationsThe Attempt at a Solution IMO , b-a = 2+ 2 = 4 for part b , why b - a = -1-(-2) ? Is there anything wrong with this question ?

Homework Statement why we need to consider 2 conditions , the beam curve downwards ( as in 11-3) and beam curve upwards ( as in 11-4) ? What's the difference between 2 cases ? I notice that in both cases , the author assume clockwise as positive here are the 3 consecutive pages of notes...

Homework Statement In the link at 12:35 , the author show the equation of the displacement of the beam without explaining , can someone try to explain why we need to use 3 Φ , 2EI / L , 2θa and 2θB ? I have no idea at all . Homework EquationsThe Attempt at a Solution