Multiple Definition and 1000 Threads

Homework Statement Find I_1, I_2 and I_3 if the switch, k, is closed using Kirchhoff's Rules. Homework Equations V=IRThe Attempt at a Solution I've had multiple attempts at this and this one is the one that came closest to a solution. Setting up 3 equations: 1) I_1 = 1_2 + I_3 =>...

Hello all; I'm doing work for my job, and I've forgotten my statistics =(. I first want to know if what I'm trying to do is possible. I want to create a linear regression of the form Y = a * x1 + b * x2 + c. http://imgur.com/Q4vGP" As you can see, there is space that is grayed...

Hi, guys, I have to read from a big txt file into multiple small .tsv files. But I was blocked at the file name. Since according to the definition of ofstream, the filename is constant char *, then is no way to modify the filename, which results in unable to write multiple files...

Homework Statement I will present a vary simplified version of the problem I am trying to model. Essentially I took 100 people and split them into 10 groups. To each group I tried to sell them a product. To the first group I priced the product at $5, to the second I priced it at $15, to the...

Homework Statement There are four points. The electric potential difference between points 1 and 2 (V12) is 30V, the electric potential difference between points 2 and three (V23) is 50 V, and the electric potential difference between points 4 and 1 (V41) is 60 V. What is the electric...

I am not sure if Multiple regression is what I want. I essentially have a function Y that is a function of three independent variables. I have a collection of points which have given Y-outputs. So when given the inputs (1, 30, 60), Y = 5. When given (1, 30, 210), Y=8. When given (2, 70...

When I start University in the fall, I was wondering how it works if you'd like to be in multiple programs. Say I were to Major in physics with a minor in computer science or mathematics, does it cost extra money? Also, do you get charged money based on how many credits you take?? The tuition...

Hi, Lets say I have the following attributes... Body fat percentage, Body mass index Outcome = obese (yes / no) I have data for all attributes and outcomes. What I'd like to do is a joint probability. For example I'd like to know what the probability is of someone being obese given their...

Hi The answers i picked are: 1)B 2)C 3)B 4)A 5)C 6)A Can someone tell me if my solutions from the attachment are correct. P.S

Electric Potential Energy Among Multiple Charges kinda aurgent [b]1. Homework Statement Four point charges, fixed in place, form a square with side length d. (See image) http://i23.photobucket.com/albums/b354/h4llw4x0r/notSoFast.jpg The particle with charge q is now released and given...

In QED, Feynman talks about P(A to B), the probability that a photon starting at a particular point in space will travel to a different point in space (I've since learned that P(A to B) is actually the Feynman propagator, unless I was midled). What I'm wondering is - what happens if there are...

How to compute E[X|Y1,Y2]? Assume all random variables are discrete. I tried E[X|Y1,Y2] = \sum_x{x p(x|y1,y2) but I'm not sure how to compute p(x|y1,y2] = \frac{p(x \cap y1 \cap y2)}{p(y1 \cap y2)} If it is correct, how can I simplify the expression if Y1 and Y2 are iid?

So, Bayes' Theorem states P(H|D) = P(D|H) X P(H) / [P(D|H) X P(H) + P(D|~H) x P(~H)], where ~ = negation If my hypothesis consists of two events - S and O - would this be P(S,O|D) = P(D|S,O) X P(S,O) / [P(D|S,O) X P(S,O) + P(D|~S,~O) x P(~S,~O)] or this P(S,O|D) = P(D|S,O) X...

Homework Statement A hemispherical piece of ore of radius a contains flakes of gold. The flat base of the ore is in the x, y plane and its curved surface is in the region z > 0, where x, y, z are cartesian co-ordinates with origin at the centre of the base. The gold density is kz kg m−3, where...

Hi Everyone, First time poster, longtime viewer of these forums. Love the help that the community gives. Just so you know where I am coming from: I am trying to calculate the average power by first calculating the total energy of my system. Specifically I am looking at the energy...

Homework Statement Trying to find out correct answers to multiple choice. Homework Equations None The Attempt at a Solution I have an important physics test coming up and I tried the multiple choice questions from a past paper, but unfortunately there is no memo. Could someone...

Hello, I wanted to ask, is it possible for a magnetic lens to have many focal points, when the magnetic field of the lens is sufficiently large? if so what is the reason for this? how does this give better resolution of images compared to a simple optical lens. I know for a normal optical lens...

A boy traveling on a skateboard steps off the board perpendicular to its motion. After stepping off, the boy lands on the ground and comes to rest. Which one of the following statements is INCORRECT? A The boy exerts an impulse on the ground on impact B The ground exerts an impulse on the...

Hey Guys, I am converting my code from MATLAB to fortran. Now in MATLAB it is rather convenient to write a function which returns multiple variables. I believe a function in fortran can return only one variable. I think a subroutine can return multiple variables. I was not able to find any...

I'm doing some practice multiple choice questions for my class and I would like to check my answers for some ones I wasn't entirely sure about. Any explanations would be really helpful. 1)What is the acceleration of an object of mass 4.5*10^-5 kg with a charge of 9*10^-9 C under the influence...

I was thinking about the Andromeda paradox and the following occurred to me. Any thoughts on whether this would be possible? I'm driving my car in a remote, non-light polluted location and ahead of me, just above the horizon. I see a very-distant star (a supernova). Just then, I see the...

hi, I'm ran into a problem while creating a Matlab GUI and I can't seem to find out why. I'm trying to get multiple lines in one static text. I set the 'max' property on 12 and then wrote the following code to test: A='a';B='b';C='c';D='d';E='e';F='f';G='g';H='h';I='i';J='j';K='k';L='l'...

The multiple coils superconducting maget is uaually quench protected by bypass diodes. The heat spreading model is mentioned on textbook for coil to coil quench spreading. But the heat spreading is not fast enough for magnet quench protection. Because the theoretical quench protection...

Hello, I have a long equation and using Mathematica 7 I want to factor out terms such as x,y,xy, x^2y,xy^2, etc. so that I'll have it in a form similar to a + b*x + c*y + d*(xy) + e*(x^2y) + f*(xy^2) + ... I've tried using the Collect by passing {1,x,y,xy,x^2y,x y^2,...} as the terms to be...

hi guys Do you know a way of identifying the winding that has multiple taps? Do you know some material on internet that explain this better?

I have a quick question. Right now, I have an offer from an REU that I have to respond to by Wednesday. However, I applied to 2 other REUs that I would like to hear back from first, but whose decisions won't come out until mid April. I know that other people on this forum have mentioned emailing...

Ok, I can plot a single polynomial easy enough such as 3*(x^2)-1 using fplot, but I want to graph multiple polynomials. When I try to use the plot it doesn't work even for one though. The graph is completely wrong. ie I make a new m-file. x = [-1:1]; y = 3*x.^2 - 1; Then call the...

Homework Statement Find the volume of the region bounded by the planes x = 0 and z = 0 and the surfaces x = -4 y ^ 2 + 3, and z = x ^ 3 y. Homework Equations The problem is listed in the book in the section Multiple Integration - Application of the Double Integral. The Attempt at a...

Homework Statement Five identical non-interacting particles are placed in an infinite square well with width L = 1 nm. I am asked to find the energy of the system if the particles are electrons. Homework Equations The time-independent Schrodinger equation for a system of two particles...

What must be true for two objects of the same material to have the same internal energies? (Choose all that apply) a. The masses of both objects must be equal b. Both objects must have the same density c. The temperatures of both objects must be equal d. Separate objects cannot have...

I am having the hardest time proving that "The product of any two even integers is a multiple of 4." My proof seems to be going in circles! Any guidance would be amazing!

Say we have a decay of the form A e^{-a x} + B e^{-b x}. I haven't had much luck trying to calculate the half-life of such a decay (I'm not sure it's possible, analytically), i.e. solve A e^{-a x} + B e^{-b x} = \frac{A+B}{2}. However, if that's not possible, I'm wondering whether...

Just wondering why there can be more than one delta solution for epsilon/delta proofs of a limit. I mean, shouldn't there just be one delta that can be used at any point on the function? Why is it that there is more than one and you choose the minimum delta..? I saw a geometric representation of...

Hello, this is my first time posting on this forum and I have seeked help on this forum before on previous assignments for my physics class. There are four problems that I do not understand clearly or do not understand how the image is portrayed in a blueprint format Problem 1 Homework...

Homework Statement Homework Equations E = (q(R-R')) / (4*pi*epsilon*|R-R'|^3) The Attempt at a Solution Ignore the MATLAB part of the problem .. i can do that easily. I just need a head start ... so should i first calculate the E between the specified set of points and each...

Hi guys Is it possible for a matrix to have more than one eigenbasis? Niles.

Hello, The following is identity no. 4.624 in Gradshteyn & Ryzhik's Table of Integrals, Series and Products: \begin{equation} \int_0^{\pi}\int_0^{2\pi}f\left(\alpha\cos\theta+\beta\sin\theta\cos\phi+\gamma\sin\theta\sin\phi\right)\sin\theta d\theta d\phi=2\pi\int_0^{\pi}f\left(R\cos...

Homework Statement Multiple choice question about a modulus function, which statement is false? Below is the multiple choice question about a modulus function (the domain of the function is all reals): Which one of the following is not true about the function f(x)= | 2x+4 | : A. The...

Homework Statement 1. If A is a real symmetric matrix, then there is a diagonal matrix D and an orthogonal matrix P so that D = P T AP. a. True b. False 2. Given that λi and λj are distinct eigenvalues of the real symmetric matrix A and that v1 and v2 are the respective eigenvectors associates...

Hi can someone please help me with these multiple choice questions A sphere of mass M, radius r, and rotational inertia I is released from rest at the top of an inclined plane of height h as shown above. 1. If the plane is frictionless, what is the speed vcm, of the center of mass of...

Hi, I have some conceptual problems regarding multiple integrals,out of which some often make me do sums wrong. Please help me out! 1. If we triple integrate a function f(x,y,z) within appropiate limits (there are some sums of this kind in my book) are we integrating in...

the problem: evaluate the following integral by making appropriate change of variables. double integral, over region R, of xy dA R is bounded by lines: 2x - y = 1 2x - y = -3 3x + y = 1 3x + y = -2 my attempt: let 2x - y = u, and let 3x + y = v then the new region in (u,v) coordinates...

Determine whether the given set S is a subspace of the vector space V. A. V=P5, and S is the subset of P5 consisting of those polynomials satisfying p(1)>p(0). B. V is the vector space of all real-valued functions defined on the interval [a,b], and S is the subset of V consisting of those...

Don't know if this is the right place to post this, but I have a friend with MS :cry: and need to know...:confused: Researchers note that doses of cannabis (marijuana) have been shown to reduce the muscle spasms experienced by many people who have multiple sclerosis. The use of medical...

I assume that if one has several current loops that the magnetic fields that they generate just add together linearlly. Just want to make sure.

Hello all. I am currently reading 'The Elegant Universe' and I'm puzzled by one key thing that is really starting to 'niggle' me! How can a one-dimensional string have multiple windings along a two-dimensional circular spatial dimension ("Garden Hose"). For this to be possible the string...

Hello All, I have been working on this problem for a few hours now and it's really beginning to bug me. I did a search on Google for methods of monitoring multiple push-buttons (tact switches in my case) using a single analog IO pin from a microcontroller. So far, I have come across a few...

Homework Statement Find the x-coordinate of the center of mass of the composite object shown in the figure. The sphere, cylinder, and rectangular solid all have a uniform composition. Their masses and dimensions are: sphere: 200 g, diameter = 10 cm; cylinder: 450 g, length = 11 cm, radius =...

Two massive lead balls are sprayed with a thin veneer of positive charge. They are isolated and at rest in inertial frame K. The positive charge is such that the electrostatic force of repulsion exactly cancels the gravitational force of attraction. Viewed from frame K’, the Lorentz force on...

Here is the question 5. A long board is free to slide on a sheet of frictionless ice. As shown in the top view above, a skater skates to the board and hops onto one end, causing the board to slide and rotate. In this situation, which of the following occurs? A) Linear momentum is...