String Definition and 1000 Threads

Hi everyone, I am trying to understand some things about confinement in lattice QCD. It has been very difficult so far to find a clear book chapter or review article, so I had to resort to the original literature in many cases, and I came across some apparently incompatible statements about...

Homework Statement (∂^2 u)/(∂t^2 )=a^2 (∂^2 u)/(∂x^2 ) x∈(0,l) t>0 u(0,t)=0 ; ∂u/∂x(L,t)=0 u(x,o)=u1; ∂u/∂t(x,o)=x I can not figure out physical interpretation of boundary condition ∂u/∂x(L,t)=0, what does it mean. Can someone can help me with this ? Homework Equations The...

Homework Statement During the experiment you will be collecting data similar to that in the table below. The experimental set up is the same as that described in your lab manual. Complete this table. Assume that the frequency is 50 Hz, and is known accurately. this is the data given. 1...

Homework Statement Two boxes are connected by a cord running over a pulley. Box A sits on a table and has a mass of 5.0 kg while box B hangs freely and has a mass of 2.0 kg. Box A moves to the right and box B moves downwards. If the coefficient of kinetic friction between box A and the table...

Homework Statement There is a ball spinning on a string in a circle in a horizontal plane in a gravitational field. What is the rotational frequency w in terms of the angle of the string to the normal line of the plane of motion, the length of the string, m, and g? The original homework was...

I'm not sure if this question is something that has been asked before or if i thought about it myself or if it's completely ridiculous! But I was thinking, if, according to String Theory, particles are 1-dimensional strings that go through modes of oscillation, could they describe how a...

Hello, My name is Holly... I'm new here... so i have no idea weather I put this in the right section! D: ... Sorry if so :3 Basically, I have been put to the task of writing a paper on String Theory and weather or weather not String Theory/ M-Theory (i can do either one, will do the...

Can anyone give me a general sense of what the quantum master equation (or BV master equation) is and how it relates to string theory? I'm an undergraduate physics student and am hoping to do research with a professor on the topic, but need some basic knowledge on the subject.

Homework Statement A brother and sister try to communicate with a string tied between two tin cans. If the string is 9.5m long, has a mass of 55g and is pulled taut with tension 6N, how much time does it take for a wave to travel from one end of the string to the other? Homework Equations...

Homework Statement If the string is mass 9.5 m long, has a mass of 55g and is pulled taut with a tension of 6N, how much time does it take for a wave to travel from one end of the string to the other? Homework Equations v=√(T/M) M=mass/length The Attempt at a Solution First I...

Good evening. I am wondering if string theory and loop quantum gravity could be combined into a single theory. I have been trying to decide which of the two I should choose as my "religion," but I feel that both are correct. Could string theory and loop quantum gravity be different...

I have read in a couple different places that the math that comes out of string theory has helped a couple of different other branches of physics like quantum computing and condensed matter physics. Quote from: http://www.ams.org/news/math-in-the-media/11-2011-media "Maybe string theory is...

I am doing a project, where I am measuring the tension exerted by different guitar strings from different sets for the classical guitar. I have a Vernier dual force sensor to do it, so the method would be just attaching one end of the guitar string to the Vernier sensor, while the other end...

Homework Statement In the attachment! This is a multiple choice question where you have to choose one of the strings. Intuitively I chose Z as I would think that in the first fraction of time it would feel the force acting on it first. However, if this wasn't a multiple choice I...

I felt like learning a bit about file input and output in C++. Tried some code, couldn't get it to work unless I made the path to the file a string literal, not a variable type. Why is this, and is there any way to get a string data type to be inputted as a path?

Hello all, I am currently a Junior in High School with a deep interest in Physics/Mathematics, specifically in the area of theoretical Physics and String Theory. I was accepted to a summer course on String Theory and am quite excited. The course stated that the only prerequisite is Single...

Homework Statement You are designing a two-string instrument with metal string 35.0 long, as shown in the figure . Both strings are under the same tension. String has a mass of 8.45 and produces the note middle C (frequency 262 ) in its fundamental mode. To extend the range of your...

Homework Statement I'm trying to read a string from cin. When it hits the "cin >> strWord" statement, I get the following error message: Segementation fault (core dumped). The input file is named "data4nine". I'm really not sure what a segmentation fault is and why I'm getting it The...

Homework Statement A uniform beam of mass M and length L is mounted on a hinge at a wall as shown in the figure. It is held in a horizontal position by a wire making an angle (theta) as shown. A mass m is placed on the beam a distance from the wall, and this distance can be varied...

This is the problem I'm working on: http://i.imgur.com/PBMFG.png I'm very behind with normal modes and waves, and I need to figure out how to do this sort of question in time for my exams, so I'm hoping that you guys will be able to help me see how this can be answered. I've answered the...

Hi all, I have a conceptual question about the net force of a rotating or spinning ball attached to a string. If we have a situation such as a tether-ball game where the ball is being swung around a string at an angle to the vertical, is the net force the tension in the string, or the...

Homework Statement A string of length a is stretched to a height of y when it is attached to the origin so making a triangle with length L=\sqrt{a^{2}+\frac{y^{2}}{a^{2}}} and therefore a length extension ΔL= \sqrt{a^{2}+\frac{y^{2}}{a^{2}}}-a which simplifies to...

This is the problem I'm working on: http://i.imgur.com/PBMFG.png I'm very behind with normal modes and waves, and I need to figure out how to do this sort of question in time for my exams, so I'm hoping that you guys will be able to help me see how this can be answered. I've answered the...

I am confused about what area is being minimised in the nambu goto action..the one in the target space or the one in the parameter space? From Zwiebach's book I think he is trying to construct the area in target space and in the process we get derivatives with respect to parameters since each...

Hi, I was wondering what the scope is these days to do a PhD in theoretical physics, but without delving into string theory? Is the world of theoretical physics still very much dominanated by string theory, or can young physicists go down alternative routes? I seem to remember that some years...

The appearance here of threads such as Causes of loss of interest in the String program and Is string theory really science? are for me a symptom of the frustration of modern physicists struggling to formulate in a predictive way the concept of elementary objects that are geometrically linear...

HELP: Solving for equation of linear mass density of a string Homework Statement You will plot frequency vs. number of segments and determine a slope. Write the expression which will allow you to solve for the linear mass density of the string in terms of L, T, and the slope of your plot...

Homework Statement I came across some codes that calculate the smaller string using user-defined functions. I tried figuring them out, but some parts I don't get. This is the first one: bool isShorter (string& s1, string& s2) { // the string objects may be large! return...

Hi there, I have a very basic question about string tension. Say I have a mass at the end of some string whirled around in a vertical circle. At the top of the swing why is there still tension? I get that if the speed of the mass is large enough some tension would be needed to supply the...

Homework Statement http://desmond.imageshack.us/Himg339/scaled.php?server=339&filename=53171696.jpg&res=medium Homework Equations GPE = mgh, EPE = λx^2 / 2l The Attempt at a Solution I'm taking the horizontal line through A as the zero-level for potential energy. Clearly, the...

I am writing a MIPS SPIM program that will take integer input, and output the corresponding words. For example, if 123 is input, then one two three will be output. I can input an integer but I get zero repeating infinite times as the output every time. Any help is appreciated. My source...

Homework Statement so there's a 6 kg rock spinning in a circle with a string that can with stand a maximum tension of 75 and a radius of 1.5m and i need to find the maximum speed before the string will breakHomework Equations Fnet=ma a=4\pi2R/T2 The Attempt at a Solution so Fnet =ma and a =...

Homework Statement A string with mass density u = 9.00 g/m extends from zero to infinity along the x-axis. It is under tension T = 25 N, and is driven by a mechanism at x = 0. The velocity of the drive mechanism depends on time as: vy(t) = 0 (if t = 0) 10.0 cm/s (if 0 < t ≤ 0.1 s)...

Homework Statement Two blocks are connected by a string that goes over an ideal pulley as shown in the figure and pulls on block A parallel to the surface of the plane. Block A has a mass of 3.00 kg and can slide along a rough plane inclined 30.0° to the horizontal. The coefficient of static...

hi all, i have the following code: do n = ninit,nlast character(len=20) :: filename integer :: n do n = 1,600 write (filename, "I0") n open (unit=110,file='wave'//trim(filename)//'.dat',action = 'write',status = 'old') do i = iinit+1,ilast-1 !boundary condition...

Homework Statement a thin wire of crosssection area 10^-2 m^2 is used to make a ring of radius 1/10 m. it is given ω=2 rad/s on a smooth table about its centre. find stress in ring?( mass/length of wire is 1 kg/m.) Homework Equations s=f/a f=mv^2/r The Attempt at a Solution my...

Homework Statement Calculate the tension in a 5 m string attached to a 4 kg bob that is moving in horizontal circles of 0.6 m radius. Homework Equations The Attempt at a Solution α= tan-1 0.6/5 = 7 degree T cos α = m*g T= m*g/cosα T=4*9.8/0.12 T=326.6 N I...

Homework Statement A string of mass 38.5g and length 5.60m is secured so that it is under tension of 220N. A wave with frequency 178 Hz travels on the string. Find the speed of the wave and the amplitude of the wave if it transmits power of 140 Watts. The Given answers are: 179 m/s and 1.35 cm...

Homework Statement A pulse takes 0.1s to travel the length of a string. The tension in the string is provided by passing the string over a pulley to a weight which has 100 times the mass of the string. What is the length (L) of the string? What is the equation of the third normal mode...

Homework Statement A small smooth ring R of mass 0.1 kg is threaded on a light string. The ends of the string are fastened to two fixed points A and B. The ring hangs in equilibrium with the part AR of the string inclined at 40° to the horizontal, as shown in the diagram. Show that the part...

A small smooth ring R of mass 0.1 kg is threaded on a light string. The ends of the string are fastened to two fixed points A and B. The ring hangs in equilibrium with the part AR of the string inclined at 40° to the horizontal, as shown in the diagram. Show that the part RB of the string is...

I read somewhere that one power of string theory is that there is no adjustable dimensionless parameter in the theory. Why is this considered a strong point in favour of string theory? Second, how does the theory help in solving cosmological constant problem? Again there is no adjustable...

Homework Statement To make it easier on the people who will try to help me, I've scanned the problem: We are interested in finding the following variables: Angles a and c The tension between A and B (TAB) Homework Equations The pulley is a "perfect pulley" no friction The system...

A ring of weight 2N is threaded on to a string whose ends are fixed to two points A and B in a horizontal line. The ring is pulled aside by a horizontal force P Newton parallel to AB. When the ring is in equilibrium the two sections of the string are inclined to the vertical at angles of 40° and...

I am trying to write a function that will detect multiple spaces, tabs, and newlines and replace it with a single string. Here is what I got so far, I keep getting errors about using a void expression and making an integer from a pointer without a cast. Please help I am really new to...

Homework Statement A girl in an elevator is holding one end of a string, and a weight hangs from the other end. In which of the following cases is the magnitude of the tension in the string greatest? (a) while the elevator moving downward and it is slowing down (b) while the elevator moves...

Homework Statement The figure shows a wave on a string moving to the right. For each of the points indicated on the string, A-F, state whether it is moving: I. upward, II. downward, III. instantaneously at rest. Homework Equations N/A The Attempt at a Solution I got A and D as...

Homework Statement My group and I have been tasked with choosing a string length so that a mass attached to two springs and the string, dropped from 4.29 meters, will fall within 25 cm of the ground. On the day of the drop we will be given the mass. We will use two springs that we already have...

The scientific method says that if experiments or observations falsify a theory, that theory must be rejected. String theory requires space to have 9 dimensions. But observation shows that our space has only 3 dimensions. This alone should falsify string theory. I know that scientists have...

Hi, I am writing a Matlab function(script), which take some input. I have several datasets in the workspace, say dataset1,dataset2,dataset3, ect In my function, I have tried to use data = input('Please input your dataset', 's') and then use 'data' as a variable for some computation, say...