Strings Definition and 548 Threads

Here's the picture of the situation described, provided by the question. Here's a screenshot of the work I have done. Here's a screenshot of the submission screen. The issue is that I have one attempt left and am not sure what I am doing wrong. Based on the hints, I feel like I'm...

Hi everyone I'd like to cut and paste a list of words into an array. I'll need to put quotation marks around them all. Is there a way to do this other than to go through each word one by one? Thanks

Hi I am doing a physics investigation on the research question "If the string length changes (same tension) does the spread and amplitude of harmonics change?". If I'm not mistaken, plucking energy should be a control variable. So, I want the energy of my plucks to remain consistent (through...

This is an exam question - refreshing as usual. Literature Overview; In the free-body diagram shown above, we can see the horizontal and vertical components of the tension forces, T₁, and T₂. Forces are vectors, which means they always have both magnitudes and directions. Like all vectors...

regepxal is showing infinite matches and shows "baaaaaaa" as a match. Doesn't (a|b) means a or b? * means match 0 or more times. So, it should be matching aa,aaa,bb,bbb, , etc? I'm not getting how baaaa is a match. Can anyone clarify please?

I am using "Introducing Python" (Lubanovic) to teach myself Python. I read that Python strings are immutable, then I see code like this - string1 = 'base_val' string1= 'new_val' not throw up an error. A little investigation shows me that the interpreter created two strings and string1 is a...

I was reading an article by Edward Harrison, which tackles the problems of conservation of energy at cosmological scales. At some point (point 2.4) he cites several article, including one by Rees and Gott, which he says indicates that the internal energy of a comoving volume (e.g. a cosmic...

Sketch

The calculation of the vacuum energy density gives us a discrepancy with reality. There should be a mass equivalent of about $10^{96}$ kilograms. I'm wondering if the assumed point-like "structure" of particles could be the cause of this wrong value. Since string theory doesn't assume a...

Diagram Problem If the mass of the block is too large and the block is too close to the left end of the bar (near string B) then the horizontal bar may become unstable (i.e., the bar may no longer remain horizontal). What is the smallest possible value of x such that the bar remains stable...

I asked about this some years ago but I cannot remember into which forum board I put it, but I wanted to know why the brightness of nylon bass strings go dead so fast on classical guitars and the related. I found an explanation in an online article, under the heading, String maintenance: Why do...

Here's the following code I've written for generating strings of length k given a CNF grammar ( Chomsky Normal Form grammar ) ( The code is a recursive variant of the CYK algorithm ). The algorithm is recursive and uses memoization. def generate_language(rule_dict, start_var, k): mem =...

I'd like someone to check that this solution is right, and if not, give me the point of failure and not the answer. Thanks!

I have already solved this problem, just would like to double check something with you conceptually. I've got a negative result for the tension in the lower cord. Intuitively I think it is right, because the lower cord does not support the ball in its opposing the force of gravity. It actually...

Someone pls solve this. I've done it but I'm not sure if it's correct. Thanks!

Let us suppose I have a string in this form, string = 'CıCCkCnow CwCho CyCou CaCre but CwChat CaCm CıC' Now I won't to take each word between 'C' and convert it into an upper case letter. For example, the above string should turn into new_string = 'I know Who You Are but What Am I' what kind...

For fun, I have decided to implement a simple XOR encryption algorithm. The first step is to convert messages into bytes to perform XOR operation on each bit. The problem has started here. For instance, I want to encrypt this message. I hiked 24 miles. Now I need to turn this text into binary...

Please see the end of question 2 of this document: https://www.damtp.cam.ac.uk/user/examples/3R1d.pdf What does Tong mean by "Show intuitively how a distant object behind a cosmic string may appear as a double image"? [For reference, the cosmic string in question is described by ##(T_{\mu \nu})...

I'm learning string theory from the book by Zwiebach and others. I'm trying to understand the quantisation of the open string and its mass spectrum. In light-cone gauge the mass-shell condition of an open string is given by: $$M^2 = 2(N - 1)/l_s^2$$ where ##N =...

Hi, I have a simple Python algorithm in my Jupyter notebook , to reverse a string. It works well on numerical strings, but when I try to reverse a letter string, I get an error message, e.g., the string abc, I get the error message: name 'abc' is not defined This is my Python code def...

Please help me on this question I have tried to do it many times but I end up getting the wrong answers. I have show my work what I have done.

I have a DATA.txt file which contains lots of useless info. I get the informations I want typing in my terminal grep freq DATA.txt and the output is the following: freq ( 1) = -0.193719 [THz] = -6.461768 [cm-1] freq ( 2) = -0.193719 [THz] = -6.461768 [cm-1]...

First i calculated the sign Force which was 4*9.81 = 39.24N which meant that the force already exceeds the traction force. What i don t understand in the question is how the distance h will avoid this?

I'm working on a problem involving the following action: $$S_1 = T_{p+1}\int{d^{p+2}\sigma (\frac{1}{4}\alpha'^2 F_{\mu\nu}F^{\mu\nu} + \frac{1}{2} \partial_\alpha X^i \partial^{\alpha} X^J \delta_{ij}+ \text{interaction terms})}$$ which represents the action of an effective free string theory...

I know string theory is already controversial enough and may even be falling out of favor among many physicists. But assuming it is right, I have heard string theorists say that strings are the "fundamental building block" of the universe. How do they make this assertion so confidently...

Do quantum strings have a specific strength, as in how much does it take to break the fabric of our universe if even possible? What would happen if it is broken or has happened?

Hi, I was given the task to read this paper https://arxiv.org/abs/hep-th/0204051 entitled "A semi-classical limit of the gauge/string correspondence" by Polyakov. On page 7 of this paper it is mentioned that the maximal radial coordinate of the string is p0 and that the string is constrained by...

I don't have the requirements (thorough knowledge of SRT, ART etc.) to get into this theory, but I would like to get an idea about this word. For the simplest case of a one-dimensional string, it is compared to a string from a musical instrument. Now the question is, what this string should...

I don't understand the working shown on the website (seen above). Firstly, they establish 'up' as the positive direction for acceleration, so A is +4 and D is -4. They create two points, P and Q, and set acceleration values for them. I understand that connected particles have the same...

Question Is there anyway to copy the content of a string into a C-String and make the length of C-String the right length of the string? This is the program I try to do, of cause this is NOT working. I don't know of any way to do this. I just want to run by you experts whether it's possible...

Attempt: By drawing the Free Body diagrams and calculating the different tensions, I got the following results ##T_1=\frac{(M_1+M_2)}{2}g## ##T_2=\frac{\sqrt 3(M_1+M_2)}{2}g## ##T_3=M_2g## But, I am not sure what the answer is as although ##T_2>T_1## but ##T_3## does not depend on ##M_1##...

Quite a long time ago, I read about length of strings in string theory. And, if I remember correctly, expected length was in light years. I looked at Wikipedia today, and I see currently expected length of string is very small, around Plank size. Is it changed over time, or the expected length...

Given the total angles in the x direction, I set up this: (mg/cos(x))*sin(x)-Fe=0 then isolated for x: mgtan(x)=(kq^2)/(2*sin^2x) sin^2(x)*tan(x)=(kq^2)/(2mg) From here I am stuck. How do I go forward when x is contained in two different trig functions on the left?

Q.1. The length of a stretched string fixed at both ends has a length of l=10 cm, mass per unit length ρ= 0.01 gm/cm. If the tension ' T ' is produced by hanging a 11 kg weight at both ends of the string, then calculate, a) The wavelength of the first two harmonics, b) The speed of the wave...

I imagine the system where P is in the middle between A and B, and P is also in the middle of light elastic string. Between P and B, there is tension force acting downwards on P. Between A and P, there is tension force acting upwards and because P is in the middle of the elastic string, there...

Say I have a dozen of strings like this, with different content between the bold markup tags ("Re:" is also a constant). I need a regular expression that will match this. Basic and I think I am close, but just need a little help. Here is what I have, but it's not matching (?<=)Re:.*?(?=]) or...

Hi new to the physics world and the symbiology is hard to understand completely. Attached is the work I've done to a final solution but I can't seem to get the answer in terms of only density of water and T1 and T2. Thank you for any assistance. [ Mentor Note -- Word file replaced with a...

Attached is what I have so far. I believe it is done but I am not 100% sure. It seems to me like every case is considered. For each state, and output of a,b, or c is possible.

Hi, Can some body please explain me the following question: Use induction on ##n## to show that ##|t^n| = n |t| ## for all strings ##t## and all ##n## . Any idea how to that. I know we have a base case and an induction case but what would be the base case and what would be the induction case...

I understand that strings have a size of roughly the Planck length ##l_P## of ##10^{-35}## m. If that is the case then one would expect that their mass would be roughly the Planck mass which is an enormous ##10^{19}## GeV. (Strings that have small spins, like standard model particles, are...

Answer says, 'any (x, y) satisfying 2(a^2)x = (x2 + y2)^(3/2)

I tried to do the free body diagram of the problem, but I{m confused because the rule is inclined. Should I just use the given angles to calculate the forces on x and y? Also, how should I calculate the torques? Since I don't know the dimensions of the rule. Can you help me? I think that once I...

I'm new to prorgramming . I have been working with Fortran90 for my physics project and I have to read data from a file. I need to find a specific matrix and then print the said matrix onto a different file and diagonalize it. How do I read the matrix that follows a specific line from a file ...

I am reading the Tipler and Mosca textbook and am on the part about massless strings. I understand that in real life a string has more tension at the top than the bottom because the top part has to support a greater mass of rope. However, in other examples such as pulling a sled with a rope I...

Hi All, Every time I login to my email server and read my email, accessing a specific message, say M generates a string S, I think in dhtml. Now, I pasted the string associated with M into another tab and it gained access to the same email. I am curious as to whether someone who knew the string...

Possibly naive question. Wikipedia describes string theory as follows: The obvious next step (since string theory hasn't succeeded in describing our universe) would be to define elementary particles as 2D surfaces or 3D volumes or 4D space-time volumes, which may have vibrational modes similar...

i have a column in a dataframe that contains values in the form or tuples (example: ('A',) ) and I want to convert these values to string format so that ('A',) becomes 'A' How do I do this in python for a dataframe? Thanks.

Hello all, I have been racking my brain with this one all day and I can't seem to figure it out. I have been looking into the forces that would arise from wrapping a string, wire, etc. around your finger. The scenario is illustrated in the attachment. Basically the question is, if we start to...

Homework Statement https://imgur.com/jE8SMDR That's a drawing of the problem. I need to solve for the ? weight. Homework Equations not sure The Attempt at a Solution none, I don't want the answer, I just want the relevant equations. I haven't taken physics in a few years though (I'm out of...

Homework Statement Three particles with the same charge q are hold together by three strings of the same length l forming an equilateral triangle. The tension in each string is: a) ## \frac {K q^2 cos 60º}{l^2}## b)## \frac {K q^2 cos 30º}{l^2}## c)## \frac {K q^2 sin 60º}{l^2}## or d)##...