Strings Definition and 523 Threads

Pulley, Strings, Friction [Please..]{Mechanics}[not Solved] Homework Statement 1) I am really confused about how tension is same on both sides of pulley. Also, how do friction of pulley affect tension in string? 2) Also want to know how tension provides torque to pulley since tension in...

I read that the middle point of a string fixed between two rigid supports set in its fundamental mode of vibration has no potential energy. I would like to know the reason behind it. At the max displacement from the mean position, it must have max. potential energy.

If electrons are strings (in string theory), what happened to the string between emission at the double slit experiment and detection on the screen after it passes thru the 2 slits? Does the string splitted and joined again after the slits? Before string theory, we just say particle...

Homework Statement http://faculty.mint.ua.edu/~pleclair/ph125/Misc/PH105_exam2_1Nov_soln.pdf Similar to question two on this site. Except I'm looking for the velocity as the ball crosses the origin. Homework Equations Listed in the question. The Attempt at a Solution I got the...

Hey guys, i just started taking a course on ST and so far we discuss the closed string following Green, Schwarz, Witten. I don't see the point of constructing the Virasoro algebra (formula 2.1.85 in GSW) if the corresponding generators are zero due to the constraints. Or to put it differently...

Are these 'strings' the size of planks constant? Nothing can obtain a size smaller than planks constant...right? What I am trying to figure out is if saying strings were the size of planks constant were a good approximation if the size of them

Can anyone explanin to me how are strings related with energy, is enrgy created frmo strings or energy is something uncreated?

Homework Statement Three identical blocks, each of mass 0.6 kg, are connected by light strings. Assume that they lie on a frictionless, horizontal surface and are observed to have an acceleration of 4.0 m/s2 under the action of a force F. Homework Equations Calculate F and two tension...

Hi fellows, 'Two particles of mass m are connected by three identical springs of relaxed length l and constrained to move longitudinally. What is the potential energy when the two masses are displaced from their equilibrium positions? What I know: let k = force constant of the strings, x1 and...

Hi folks, I'm a 3rd year student doing a BSc in Mathematics and Physics (in Scotland) and I was wondering if anyone could share with me their experiences of the MSc particles, strings and cosmology at Durham (previously MSc elementary particle theory) or any of the other similar courses at...

Homework Statement Q= 2800N G= 10m/s^2 s=35m t=10s __________ Fst=? (st-String tension) Can anyone help me with this, i have a test tomorrow And if anyone can give me the formula for the Tension force i'd be really grateful.

Hi all, Alright so while reading through some stuff, I came across something peciluar, string/M-theory state that rips in spacetime are a natural phenomenon and happen all the time. "Edward Witten showed that strings, which have spatial extant, can travel while encircling the tear as it...

the question is could a STRING be a very long object with high energy wrapped into the size of the atom ?? the idea is if we could unroll an string would it deliver some kind of its energy ? for example if we have some kind of Einstein equation but for string in the sense that Energy E...

Homework Statement Considering the following diagram: http://img545.imageshack.us/img545/6301/physx1.jpg AC is a force being exerted on chords AB and AE of magnitude 600N. Chord AE is attached to to surface FD. Chord B is attached to a second surface of which no information is...

Considering that the smallest particles in nature are supposed to be strings, which are donut and line shapes. And the poincare conjecture says the simplest shape in nature is a sphere. wouldn't it make sense that the true fundamental particles are sphere shaped and that if they combine to form...

So if I leave my steel strung guitar overnight in my cold basement, it goes out of tune on the sharp side. Now if I want to manually tune my guitar sharp, I have to tighten the strings = i.e. put energy into the system and do work. So where does the energy come from to do this in a cold...

The answers will probably be "it ain't as simple as that" but here's trying, anyway. 1. Is current thinking that strings have to wind "around" something? If so, must the compactified space have at least one hole? 2. With just a single hole, presumably there can be just one topologically...

Given my limited background in Physics, I am restricted to the popular literature on M-theory. After going through this literature (including articles from the very helpful "annotated list of useful literature for String Theory" posted in this rubric of the Forum), I am still puzzled by the...

So the following questions were posed in an another thread by Pallen, and I thought i'd give an attempt at answering them, since they tend to show up over and over again. " 1) It is not clear that GR and QFT must be considered in conflict that must be resolved somehow. I've seen a growing...

Homework Statement Two ukulele strings, of equal length and mass are tuned so that the first string, when it vibrates at twice its fundamental frequency, has the same frequency as the second string when it vibrates at three times its fundamental frequency. The tension of the first string is...

Create a program in which the digits returned are reversed such as if 234 was the input the output is 432. import java.util.*; public class Test{ public static void main(String[] args){ String revNum =""; int rem = 0; int n...

Homework Statement Two small spheres, each of mass 4.00g, are suspended by light strings 15cm in length. A uniform electric field is applied in the x direction. The spheres have charges equal to -7*10^-8 C and +7*10^-8 C. Determine the electric field that enables the spheres to be in...

Three blocks on a frictionless surface are connected by massless strings, with M1 = 1.30kg, M2 = 2.20kg, and M3 = 3.40kg. Due to the force F acting on M3, the system accelerates to the right. Given that T1 is 4.10Newtons, calculate T2. M1 = 1.30 kg M2 = 2.20 kg M3 = 3.40 kg and T1 =...

Homework Statement Given the constants k_1 and k_2 and distance x, determine how much work is required to stretch the spring x from equilibrium position. Homework Equations W=\frac{1}{2}kx^2 The Attempt at a Solution All I need to determine is what my value is going to be for k...

Homework Statement The figure shows a light fixture suspended from the ceiling. If the tension in cable 1 is 34N and the tension in cable 2 is 24N, what is the mass of the light fixture? Homework Equations Image http://orbitsimulator.com/misc/IMG00034-20101024-1557.jpg The Attempt...

Hi, I would like to know what is the distance between strings (or average distance) ? and also in what manner are the strings spread across space? are they spread evenly ? can i find the exact amount of strings in any given location? thanks

A very interesting but speculative paper was published in the Physical Review and arXiv recently about the possibility of the former existence of Cosmic Strings at the point of Electroweak energies. Robert Poltis and Dejan Stojkovic http://prl.aps.org/abstract/PRL/v105/i16/e161301...

Homework Statement An object of mass 100kg is hanging from a ceiling by means of 2 strings. The 1st string (t1) makes an angle of 55 degree with the horizontal-right. The scond string 9T-2) makes an angle of 25 degree with horizontal left. Calculate tension in the first string (T1)...

Im aware that there has been some difficulties in zero dimensional particle calculations, which I suppose gave way to string theory which explains gravity. But i would like to have some more input on the exact problems when dealing with zero dimensional particles and why strings were added. Are...

Homework Statement 2 small spheres of charge "q" suspended from strings of length "l" are connected at a common point. one sphere has mass m, the other 2m. Assume angles theta_1 and theta_2 that strings make with vertical are small. (a) how are theta_1 and theta_2 related? (b) show that the...

Can the strings of string theory live in only 4D spacetime? Do we get anything interesting or useful? What do we lose? Thanks for any ideas or help!

Can someone help me with this problem? I am stuck. So far I have:net Force (x) = T1cos30 - T2cos(θ) = 0 net Force (y) = T1sin30 + T2sin(θ) - 120N - 400N = 0 From equation 1 ---> cosθ = (T1cos30)/T2I attached a picture of the problem. Not...

Homework Statement The fig has three masses m1 , m2 , m3 .. all of which are unequal. Find relation between masses so that m3 remains stationary. ( pulleys , strings are frictionless and massless) The Attempt at a Solution I thought if mass on both side are equal then the system...

In C, why do you have to define a pointer type? For a 32 bit computer, the address is 4 bytes long no matter what, so it shouldn't matter if the pointer is to a char or an int, yet I get a compiler warning when I use a char pointer to point to the address of an int. Also, I don't quite...

Homework Statement [PLAIN]http://img62.imageshack.us/img62/2120/derppz.jpg Need to find T1 + T2I can do it when the two masses are connected to each other, I was just wondering how I'd do it now there is another 5kg in the middle? Also if the acceleration is already given as 2m/s to the...

So fundamental point-like particles are expressed by the vibration of a string... yet a string is two dimensional? or even more? How can quantum mechanics not apply to strings?? I don't understand the size of strings vs the size of the particles they represent? Someone please explain!

Homework Statement A body of large mass is suspended by means of a string A from the ceiling, and another similar string B is attached to the bottom of the body. Which string would break when string B is pulled (a) sharply, and (b) steadily? Why? Homework Equations F=ma The...

Hallo I have been thinking about when beam starts to behave like string. My questions are: How much tension do you need to put on a beam before it starts to behave like a string? And when does the behaviour become purely string like? Thanks

What are the dimensions of the branes that to which it attaches? Can a string attach to other string as it were a brane? I mean, the string is 2d space time object, the twistor space is 4D, so the complement should be another string.

Hello, I am wondering if it is possible to append a number as a string to the end of a variable name in Matlab? I am working with radar data and want to create structures for each volume of data, but I do not know how many volumes are contained in each file, and I have so many files I do not...

Physics 101 (forces), Rock on Strings: driving me crazy! okay, this problem is DRIVING ME CRAZY! please help me out here, it's a TYCHO homework: Homework Statement A 540 gram rock is held by two strings of 45 cm with ends 57 cm apart (distance d in the picture), any string will break...

According to string theory, are strings Planck length in 1 dimension and 0 in all other dimensions? Or more than Planck length in 1 dimension and exactly Planck length in all other dimensions? Or something else? Thanks.

Homework Statement Find the tension in each string given the diagram.Homework Equations Fx = ma. Fy = ma. The Attempt at a Solution Fy = 0. Because it's at equilibrium. T1(sin30) + T2(sin60) - mg = 0. T1 = [mg - T2(sin60)]/(sin30) Fx = 0. T1(cos30) + T2(cos60) = 0. T1 = [-T2(cos60)]/(cos30)...

Homework Statement I need to compare a user input with a string that's already in the program. If the operation entered is ‘*’, you should print out the product of the 2 numbers; if the operation entered is ‘/’, you should print out the quotient and the remainder. the multiplication...

Homework Statement A string is attached to a ring of mass m which is free to move up and down a frictionless pole. The string is subject to tension T and its mass per unit length is \rho. The displacement of the string from its equilibrium position along the x -axis is y(x,t). The boundary...

Block of mass M between two strings on incline? A block of mass M rests on a frictionless inclined plane of angle θ as shown in the diagram below. Two springs of equal length are connected to the block and to two posts as shown. The separation between the posts is equal to the sum of relaxed...

hey, I've hit a bump in the road here. I'm trying to build code for a hash table out of my textbooks pseudo code, and I'm not quite sure how I'd represent a string of characters such as "thisISastring", as an integer for my key variable. I'm using division method if that helps at all. I know the...

Tension problem! Homework Statement Consider a force F = 887 N pulling 3 blocks of masses m1 = 9 kg, m2 = 16.9 kg, and m3 = 26.1 kg along a frictionless horizontal surface. The tension of the strings are T1 and T2 (see sketch). The equation of motion of m2 is given by 1. T1 − T2 = m1 a...

A heavy rod AB is suspended from a point O by two strings OA and OB . Show that the plane OAB is vertical. How to do this? Please help me.

here available http://mitchell.physics.tamu.edu/Conference/string2010/Conference.html And list of speakers: http://mitchell.physics.tamu.edu/Conference/string2010/speakers.html