Strings Definition and 548 Threads

Homework Statement A ball of mass 1.21 kg is attached to a rotating shaft by two strings, putting the ball into circular motion. Tension on the upper string is 35N. (The length of the strings is 1.6m) a) draw a free body diagram for forces acting on the ball. b) determine the tension in...

Homework Statement Two pendula are suspended on 70cm strings connected at the same point on a ceiling. The mass on the left is 45g and is held so the string makes an angle of 10 degrees with the vertical. The mass on the right is 65g and is held in the opposite direction so the string makes...

Homework Statement Two copper wires, one 1.0 mm in diameter and 1.0 m long, the other 2.0 mm in diameter and 2.0 m long, are joined together end-to-end and hung vertically. In order to tension this compound wire, a block is suspended from it. It is found that a transverse pulse takes 50...

One of the things that LHC will experimentally search for are supersymmetric partners of the Standard-Model particles. Maybe it will found them, maybe it will not. But what if it will? The existence of supersymmetry does not imply the existence of superstrings. However, string theory is...

Homework Statement A ball of mass 0.765 kg is tied to the end of a string of length 1.59 m and swung in a vertical circle. During one complete circle, starting anywhere, calculate the total work done on the ball by the tension in the string. During one complete circle, starting...

help me! Homework Statement Three blocks on a frictionless surface are connected by massless strings, with M1 = 1.80 kg, M2 = 2.80 kg, and M3 = 3.70 kg. Due to the force F acting on M3, as shown, the system accelerates to the right. Given that T1 is 2.70 N, calculate T2 Homework...

Hi all. It's been quite a while since I've been here, but I was reminded this morning about my childhood when a friend of mine and I got a hold of a spool of string that was purported to have been 5 miles in length. Thinking about it I think it was probably more like some 5000 feet in length...

4096 colours!? http://motls.blogspot.com/2007/08/answering-few-string-related-questions.html

Penrose proved that a more than 4-dimensional spacetime would be unstable.. does this mean that String theory is completely wrong?? (since this only works on 11 dimensions). Also without offending nobody's beliefs .. .what're the proofs for the existence of String theory ??, its math elegance...

From what I gather string theory states that everything is made of tiny vibrating strings or bands. But what force or energy causes these strings to constantly vibrate?

Hi all, I asked about this on the academic and career guidance forum but didn't get any useful replies. Which of these maths subjects (all at fourth year level) would you recommend for someone interested in the subjects listed in the title? What would you say is missing from this list...

In http://xxx.lanl.gov/abs/0705.3542 strings are derived from an attempt to formulate a more fundamental view of quantum mechanics, based on Bohmian interpretation of quantum mechanics. Such a more fundamental view is motivated by some foundational problems of quantum field theory (QFT), such...

I understand why in the presence of a constant vector potential A=-\frac{\theta}{2 \pi R} along a compactified dimension (radius R) the canonical momentum of a -e charged particle changes to P=p-eA. Due to the single valuedness of the wavefunction [itex]\propto e^{iPX}[/tex] P should be...

[SOLVED] Mass per Unit Length of Violin Strings Homework Statement Each string on a violin is tuned to a frequency 1.5 times that of its neighbor. If all the strings are to be placed under the same tension, what must be the mass per unit length of each string relative to that of the lowest...

Dark energy is said to be a property of space that stretches a volume of space in all directions.If space is made of strings, do individual strings expand in all directions? And since the universe is changing its expansion rate, do strings obey some law like Hooke's Law:force (tension) is...

What exactly are hash functions and how do you use them to create a random string? What other ways are there to create random strings.

Hi everybody I’m currently making/coding my own guitar synthesiser and I are interested in creating a 'bend' playing effect. By modifying the tension of guitar strings I presume I will be able to change the rate in which sounds travels in these strings. From playing guitar myself I thought...

When a pendulum is moving will the length of the string that the bob is attached to appear to be contracted?I have this doubt as the string is sometimes in direction of motion and at one point absolutely not in the direction of motion

I am asking is light as it is related to particles could be (wave/particle theory) could be composed of strings. http://www.geocities.com/physicsquestion2007 Has anyone seen any publications or authors who support this idea? Chris Walters

Homework Statement Two identical violin strings, when in tune and stretched with the same tension, have a fundamental frequency of 440 Hz. One of the strings is retuned by adjusting its tension. When this is done, 2 beats per second are heard when both strings are plucked simultaneously. a...

hello can some one explain this in details thank u a- How many bit strings of length seven either begin with two 0’s or end with three 1’s? ] b- How many bit strings of length 10 contain either five consecutive 0’s or five consecutive

The problem with bosonic strings is the fact that they contain a tachyon. Why that is not a problem for the bosonic part of heterotic strings?

Hello there, I am filming a documentary on cutting-edge physics, and I was wondering what constitutes a "professionally researched theory." What is it about ST and LQG that make them "professionally researched?" Are there other non-profesionally researched theories out there? Thanks...

If strings or membranes are the most fundamental entity that cannot be divided further, where do these "particles" begin? Subatomic particles such as electrons, protons, and neutrons can be further divided into quarks, fermions, leptons, gluons, bosons, ect. Do particle physicists believe that...

Hello everyone. I'm not sure if I'm doing this right or not. The problem asks: Consdier the set of all strings of a's, b's, and c's. a. make a list of all of these strings of lengths zero, one, two, and three that do not contain the pattern aa. Okay so i have the following: note e: stands...

Hi I have a question about pulses in a wire. If I have a single wire of length X and I send a pulse through the wire, when the pulse gets to the end of the wire, does it reflect back with the opposite phase or in phase when the original pulse? I'm trying to visually compare the behavior with...

Polchinski: "2006, the Year in Strings" Joseph Polchinski gave a well attended plenary lecture titled: Polchinski: "2006, the Year in Strings" http://www.phys.hawaii.edu/indico/contributionDisplay.py?contribId=746&sessionId=25&confId=3 The above link gives the slides. I found...

i need a make a program that prompts the user to enter a string, and for it to identify the uppercase characters and replace each uppercase char with the corresponding lowercase character. it also needs to count the character here's what i have so far: #include<stdio.h>...

For homework, I was given the following problem: A .5kg hangs from two strings at the angles shown. The longer string is .5m long. (a) Determine the tension in each string. (see attachment for diagram)Can you tell me how this looks... 1st I broke everything into x and y components (ie Tlx...

how to convert an input of integer(more than 1 character) type into output which is in string in c++

AB is a uniform bar of length 5m and weighs 60N. It is supported in a horizontal position by two vertical strings P and Q. P is 0.5m from A and Q is 1.5m from B. (a) What are the tensions in the strings? (Ans= 20N and 40N) (b) What weight must be applied to A if the tensions in the...

I am sure most of you have noticed how convenient the English keyboard becomes when using it to label 26 and 10 dimensional spaces: there is 26 alphabetical characters, and 10 numerical ones. I feel ready to discard the ten numerical chars as mere coincidence, but I am not so sure about the...

Three objects with masses m1 = 7.0 kg, m2 = 10.0 kg, and m3 = 14.0 kg, respectively, are attached by strings over frictionless pulleys, as indicated in Figure P5.32. The horizontal surface is frictionless and the system is released from rest. Using energy concepts, find the speed of m3 after it...

This morning an odd thought struck me: Is it possible to consider closed (oriented) strings which are entangled into each other in target space (like two rings of a chain)? Due to the topologic properties of this construction the structure should be stable, since both strings cannot interact...

I was wondering, OK it is a gedakenexperiment because it is beyond observation, but... how is space-time supersymmetry (no worldsheet susy) supossed to appear from the point of view of states of the fundamental string? Do we observe entities with spin 0 and spin 1/2 having the same mass? And...

strings as preons: does string theory allow muons to decay directly into e- + photon, given that the only difference between an electron and a muon, in string theory, is the string's tension? Of course, that's not how muons decay, (they decay into a W- boson, which decays into an electron and...

Three objects are connected by light strings as shown in Figure P4.62. The string connecting the m1 = 6.00 kg mass and the m2 = 4.80 kg mass passes over a light frictionless pulley. (b) Determine the tension in the two strings. string between m2 and the 3.00 kg mass I was able to do the...

I'm having trouble on this problem: A weight of 21 kg is suspended by means of three strings T1,T2,T3. T1 and two are connected to a ceiling and meet at their end. T3 connects at the joint section of T2 and T3. All that you are given is the angles of T1 & T2 and the weight of the object. How...

I am ashamed that no one of the textbooks on string theory take care to refer to the Leech lattice or to its (n+1,1) kin, even if only of a footnote when they use selfdual lorentzian lattices. I wonder if it is ignorance or intentional misinformation. Because the singularity of the (25,1)...

if a standing wave is a wave which transfers no energy, how is it that a guitar string produces a sound? because it produces it via a standing wave, and the sound is sound energy, so where does the energy come from?

It's been awhile since I've had physics I, so this problem is giving me a headache. Q) Two very small conducting spheres, each of a mass 1.0 \times 10^{-4}\,\,(kg) , are suspended at a common point by very thin nonconducting threads of a length 0.2 \,\,(m) . A charge Q is placed on each...

ok...I'm a dummy. been doing some novice reading on string theory lately. couple questions: are strings in 'empty space'? and if so, is this how the gravitational pull of a body is exerted on another body...thru the interaction of strings in-between? thanks.

Hi there- I've been trying to solve this problem for the last hour, and I still feel stuck! So far, I've only seen problems with equal angles between the strings and the horizontal- I have no idea how to solve a problem when there's two different angles! A 45-N lithograph is supported by two...

Hello everyone , I'm new in this forum . I'm 16 and currently doing self study in Mechanics 3 . I've encounter a problem in the 2nd chapter of Mechanics 3 which is Elastic Springs and Strings . Here goes : A ball of mass 0.5kg is attached to one end of a cord of unstretched length 0.6m...

The schedule of talks has been posted by the Beijing organizers http://strings06.itp.ac.cn/schedule5.pdf For more information: http://strings06.itp.ac.cn/

Hi, I'm scanning a code from each box to compare and see if the box scanned is a "good" box. The whole code is about 21 bytes and I only want to compare 9 bytes since those 9 bytes differentiate between the 2 types of box. I created (2) 9-byte strings in DB98, string1[9] starts at 0.0 and...

Could the members here please peacefully discuss this topic including the good and bad parts of it. So, strings are simply small waves of energy? Is there something more to this?

How do they make them so that these exquisite notes come from them, i mean they are flimsy bits of wood and tensioned strings, is there a (science) behind it ?

When I was first told that strings were able to see Einstein equations I thought, "what is the deal?". The Riemann Curvature Tensor is a two dimensional object, nothing rare you capture it by using two dimensional objects. It is well known so it is not rare that high level books do not mention...

this just appeared today http://arxiv.org/abs/gr-qc/0605087 Quantization of strings and branes coupled to BF theory John C. Baez, Alejandro Perez "BF theory is a topological theory that can be seen as a natural generalization of 3-dimensional gravity to arbitrary dimensions. Here we show that...