Strings Definition and 548 Threads

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.

Homework Statement Blocks with masses of m1= 1.0 kg and m2 = 2.0 kg are connected by a string, supported on a frictionless table, and connected by a string and pulley to a hanging block with a mass m3 = 3.0 kg, as shown (attached the doc), and released from rest. Homework...

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

This is not homework, I need someone to verify (9) and (10) below whether I am correct because I don't have the answer. I need to find the solution of the following: Question Find the solution of the equation for damping vibration string stretched from x=0 to x=L where \frac{\partial ^2...

I am doing a question (its not home work just an exercise). The following is the question. Write code that allocates space for an 80-character string and then inputs a string from the keyboard and stores it in the allocated space. This is my code. #include <stdio.h> #include <stdlib.h>...

Homework Statement String 1 in the figure has linear density 2.4 g/m and string 2 has linear density 3.5 g/m. A student sends pulses in both directions by quickly pulling up on the knot, then releasing it. Consider the pulses are to reach the ends of the strings simultaneously. In the figure...

we sway into scifiction which i want to be realistic: How is it inside Subspace or Hyperspace or a cosmic string (from the perspective of different theories)? Can we even enter cosmic strings (if we say we had the technology)? Has the subspace (enbedded in our 4 dimensions) or the...

1. Homework Statement The problem concerns a block(mass M) hanging from a light string attached to a fixed support, that is pulled down with a force of the block's weight that produces an extension of 'l'. 2. Homework Equations The elastic P.E is half of (M*g*l).However the loss in...

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...

Beat frequencies/tension force of violin strings while tuning--please help Homework Statement To tune your violin, you first tune the A string to the correct pitch of 440 Hz, and then you bow both it and the adjoining string simultaneously, all the while listening for beats. While bowing the...

Hi! I saw an interview with Dr. Michio Kaku on branes and when asked where these other universes (or is it ‘worlds’) on other branes exist, he said in your living room. (?) This doesn’t sound like the vertical wavy sheets nor the separate (or connected) bubbles we’re shown in brane videos...

Hi there PF. For this problem I need to take the following code which apparently sorts an array with integers, and sort strings instead. However I DO NOT understand how this works for integers, much less how I could make it work for strings. Could someone please explain it to me? A few tips to...

So let's say you have like a pendulum but instead of the one string you have two strings attached to two fixed supports (I tried to include a picture). Let's say you pull it back and swing it so that it is swinging in and out of the screen. Would its period of oscillation be the same as if there...

What makes the strings in string theory "vibrate"? Does string theory include or say what is responsible for making strings vibrate? Also, why do the strings not all vibrate in the same pattern; what makes a string "choose" one pattern over another?

Could the higher dimensional spaces of string theory be used by point particles? Take the idea of extra dimensions of string theory and use point particles instead of strings. Point particles need some type of internal degrees of freedom? Thank you for any help.

1.AB is a uniform bar of length 5m and weight 60N. It is supprted in a horizontal position by 2 vertical strings P and Q. P is 0.5m from A and Q 1.5m from B. a) What are the tensions in the strings? b) What weight must be applied at A if the tensions in the strings are to be equal? c) What is...

Homework Statement Two wires are tied to the 300 g sphere shown in figure. The sphere revolves in a horizontal circle at a constant speed of 6.50 m/s. What is the tension in the upper wire?What is the tension in the lower wire? Write an equation for the sum of the forces along y. Use it to...

Motion of strings may give rise to particles? Size difference about, E-35m/E-15m = E-20 Motion of particles gives rise to Universe (or Universes?)? Size difference about, E-15m/E26m = E-41 Thanks for any help.

Homework Statement You have three strings holding a 20kg weight, all tied to a ceiling above the weight, one centered right above the weight, the other two tied to the string at equal angles. What is the tension in each of the cables Homework Equations Fnet=0 The Attempt at a Solution...

1. Homework Statement : A 4.00 kg object is attached to a vertical rod by two strings (as below). The object rotates in a horizontal circle at constant speed 6.00 m/s. mass = 4.00 kg V = 6.00 m/s Homework Equations centripetal acceleration = Ac Ac = V^2/r...

so i came across string theory and i don't understand (if your going to go along with it) why it is tiny strings that make up the universe and why exactly do they have to exist in more then 4 dimensions?

This is a old one, but it is rare to find the general solution: Consider a string (a fuse) that, when burned from one extreme, takes one hour to burn, but irregularly (some pieces burn faster than another). Get two strings of this kind. The irregularities are different, you are only granted the...

Homework Statement The string connecting the m1 and the m2 passes over a light frictionless pulley. Given m1 = 6.51kg, m2 = 7.48kg, m3 = 9.75kg. The acceleration of gravity is 9.8 m/s2. 1) Find the downward acceleration of m2 mass. Answer in units of m/s2 2) Find the tension in the string...

Homework Statement A 100-N body is shown suspended from a system of cords. http://bcs.whfreeman.com/WebPub/Physics/tiplerphysics6e_bridge/question_bank_images/4-50A.png?2417 1. What is the tension (T2) in the tilted cord? Round your answer to three significant figures. 2. What is...

If a string has a Planck length then why doesn't it have a huge Planck mass? Perhaps it does but its negative gravitational self-energy counteracts this huge positive mass/energy. Maybe a closed string can be thought of as a Planck energy electromagnetic wave trapped by its own...

If you have a guitar string and you pluck it nothing happens. Not unless it is tensioned by pulling both ends tightly. In string and brane theory do the strings have something that keeps them tensioned? Or don't they need tension to maintain vibrating; unlike normal strings? Are they free...

After compiling the code below, GCC says that you can't compare a pointer to string by iso C++ standards. But I don't see a pointer anywhere (I don't know pointers for now...did it long ago, now forgot)...may be it has to do with the fact that arrays are called by reference. char...

In string theory are the strings themselves the manifolds? or are the strings vibrating in a 10 or 11-d manifold?.

This is what a book says. Is this string different from a text stream which consists of many lines?...or can a string contain many lines separated by \n?

For 30 years string theorists have said string theory is the only game in town. It is the only known consistent theory of quantum gravity. LQG has not been shown to have GR in the low energy regime so it is not been shown to be even related to gravity. The only reply I've seen is that string...

I've recently had this thought experiment, and wanted to share it. My HS physics teacher had talked about "perfect" strings that had no mass, does not stretch, and is completely flexible when describing physics experiments. Using such a hypothetical string means it does not interfere with the...

I know that answers to the following can sometimes be subjective and biased... but still... What are the most 'promising' models in string theory, judged by the potential realization of a realistic SS standard model? Also, in particular, how do Intersecting Brane Models (since their...

Consider a character string randomly generated from an alphabet {T,H} of length L, where T and H each have a probability of 0.5. For an arbitrary finite L the probability of a given string is p=(0.5)^L. A probability is the sole determinant of Shannon entropy (S). Therefore I'm claiming that...

Is there something in string theory that requires strings to be the most fundamental structure?

Homework Statement Four blocks are on a horizontal surface. <---F2---B---Tx---A---Tz---D----Ty--C---F1--> The blocks are connected by thin strings with tensions Tx, Ty, Tz. The masses of the blocks are A=41.0 kg, B=21.0 kg, C=29.0 kg, D=39.0 kg. Two forces, F1=47.0N and F2=71.0N act on...

Homework Statement Two objects of equal mass m are whirling around a shaft with a constant angular velocity ω. The first object is a distance d from the central axis, and the second object is a distance 2d from the axis. You may assume the strings are massless and inextensible. You may ignore...

Mi imaginery of a oriented string is a line with two different (oposite) ChenPaton labels pasted in the extremes, say +...- while an unoriented one has the same label pasted in both extremes, say +...+ or -...- In this imaginery a vacuum loop for oriented strings would create two strings...