String Definition and 1000 Threads

I continue my reading of Griffiths electrodynamics (chapter 9, electromagnetic waves) and I got stuck on this: Author tries to prove a stretched string supports wave motion and I found it very difficult to grasp. In the second equation, why can we replace sin function with a tangents really...

As far as I can tell (if we look at pictures, without equations), a loop can be considered as a 1-dimensional closed string; and an open 1-dim string can be considered as a loop that we cut one point on its boundary? So basically the fundamental building block is the same whether you call it...

In classical mechanics, the potential energy stored in an elastic stretched string is the work done by the tension during the stretching process. Is this concept and formula the same in Special Relativity? Thanks in advance.

Every once in a while I use my ancient trick of searching something in google with keywords, and found the above article. I don't think there's a free copy of it, because it's from 1989. I guess I need to read the pink book on foundations of Q-Groups by Majid. You know who also has written a...

In part (c), I have no problem if the string could stretch, but consider an inextensible string. This could still form a standing wave, according to google. But then how is the string (the wave) equal to L? So can we actually equate lambda/4 with L? i.e. it is curved and varies with amplitude...

Is it possible to study/observe the virbation patterns of a string within a quark? I understang that String Theory is a theoretical framework, however is it possible to make an observation linking the vibrations of the strings within the quarks to the particles produced? If so, has there even...

Did I draw the free body diagram incorrectly by treating the two blocks as one system? My textbook claims the answer is 25 N.

I'm almost certain that if it was a "steel rod" or something heavy like that, the normal (the force written in green) would exist. But does it exist for a "massless ideal string"? I mean, there is tension in the string of course, but would that cause the normal perpendicular to the wall?

This isn't a question about torsion pendulums because it goes well beyond linear physics. The question is roughly, how many times can you rotate the end of a steel string, with the other end fixed, before it breaks? Also, how does the torsion distribute along the string? I tried to answer both...

I am reading a hebrew translation of the popular book by Michio Kaku on HyperSpace. It seems Superstring Theory will never be refuted since if it's a theory of everything then you need infinite energies since the universe is infinite, and we can never get a from finite machines infinite...

For this, Is it possible to calculate the time it takes for the initial antinode at the string vibrator to become a node in the transient phase of the system? Also do we assume that once the system has reached steady state, that the mass has such a large inertia that it is stationary so acts as...

Hello everyone, I have this problem that I can't solve: I have two types of images contained in two different folders. I have to create a dataset with these images and train a cycleGAN model, but for simplicity we assume that I want to print them on monitor and forget the cycleGAN. My code is...

The statement of the problem is: Consider a taut string that has a mass per unit length ##\mu_1## carrying transverse wave pulses of the form ##y = f(x - v_1 t)## that are incident upon a point P where the string connects to a second string with mass per unit length ##\mu_2##. Derive $$1 = r^2...

I am a high school student and recently I have been working on a project about how temperature affects the frequency of a string emits. I have read blogs like https://www.physicsforums.com/threads/tension-and-frequency-with-change-in-temperature.833185/ and completed the part of thermal...

In theories of particle physics based on string theory, the characteristic length scale of strings is assumed to be on the order of the Planck length, or 10−35 meters. I am sure few people have heard about the long strings theory. If there is information on the topic big request to share it...

If we consider the coefficient b as the rings impedance, we can consider the effective impedance on the right to be b+Z2 where Z2 is the impedance of the second string. Then because there is no reflection it follows that Z1=b+Z2 or b=Z1-Z2. Is this a valid solution? My professor went through a...

I tried to come up with expression of time in terms of φ, α, and some constant value of cone size that does not depend on angle (I used R as cone radius). I though I could use that expression to see at what angle time is going to minimum, but I came up with expression from which I can't make a...

For this problem, The solutions are, However, how would we solve this without using the idea of conservation of string? Can we apply Newtons second law to each mass? My working is: Then apply Newton's Second Law to each pulley, (Line 1) (Line 2) (Line 3) (Line 4) Many thanks!

Hi, I'm trying to write a program in Python 3 to determine whether a string is a palindrome. I wrote one already ; it runs, to reverse a string. I now want to use it to determine palindromes , by testing whether a string equals its reverse. To practice slicing as well, I want to write the...

Attempted creating equations for zeros of torque and components of forces in x and y as seen in picture. Got lost with having only variables and the d & 2L for the length of the beam. Not sure how to do the question with two points of contact between the beam and the sign. Is the center center...

On page 52 in Becker, Becker, Schwarz, there is an equation (2.148) for the number of open string excitation modes. I tried to Tayler expand eq 2.145, but couldn't reproduce 2.148. Plus, one gets 2.145 by setting w close to 1; even if I use the 2.146 and try to analyze it around 0, I am still...

My answer is (1) only but my teacher said (3) is also correct. I don't understand why, I think when the wave is moving to the left both Q and R will be moving upwards, no? Thanks

I'm using C# to program in Unity and I'm having some trouble with getting a tooltip box to update every frame. Simplified, Class A (and several other classes and instances of classes) has a string that stores the tooltip text and updates it every frame. Class B contains the logic to generate the...

Thinking about Bell's string paradox , I understand that if both spaceships maintain the same and constant proper acceleration, the string breaks because of the non-simultaneity of the acceleration effects at both ends of the string. But I want to introduce and consider a slight and subtle...

I want to ask about part (c). This is what I did: the length of the shorter piece should be 8 ≤ X < 10 so P (8 ≤ X < 10) = 2 . (1/20) = 1/10 But my teacher said the correct answer is 2/10. Where is my mistake? Thanks

The speed of a wave in simple harmonic motion on a string is $$v= \sqrt{\frac{F}{\mu}}$$ where v= the horizontal velocity of the wave on a string. Is the F the horizontal force or the resultant force (combination of Fy and Fx)?

hello, I’m trying to figure out if I’m doing this correctly or if there’s a different way that I should be finding a missing value. I’m trending data for an automatic transformer. Every month I collect the operations counter value and at the end of the year sum the number of tap changes...

F(n)=##n^2 −n+41## generates primes for all n<41. Questions: (1) Are there polynomials that have longer lists? (2) Is such a list of polynomials finite (yes, no, unknown)? (3) Same questions for quadratic polynomials?

How did they impose boundary conditions here if "no end" is selected? Here: https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html I would like to do the same thing without changing the wave equation of the string.

On ***page 38*** of Becker Becker Schwarz, we're given ***equation 2.69*** which is the Hamiltonian for a string given as $$H=\frac{T}{2}\int_{0}^{\pi}(\dot{X}^{2}+X^{'2})$$ Considering the open string we have...

Yarn Grippers, Linear motion equipments Motors

I need help with this homework question and I'm blanking out. Can anyone help me to answer this question correctly.

What do you recommend to read first, Supergravity by Freedman or A First Course in String Theory by Zweibach? For future consideration.

Roughly how many people in this world actually know about string theory? I'm guessing no more than a few hundred because the math of string theory is so esoteric.

one of the claimed successes of string theory is its ability to derive the correct Hawking-Bekenstein equations to calculate the quantum entropy of a black hole without any free paramenters, specifically Extremal black hole entropy using supersymmetry and maximal charge. I was wondering if...

My textbook is deriving wave speed on a string under tension with confusing thetas. It assumes ##\tan \theta_1 = \frac{-F_1}{F_T}## and ##\tan \theta_2 = \frac{F_2}{F_T}## which confuses me. I know for sure theta is the angle due to the position of y and x, ##\tan \theta = \frac{y}{x}##, but I...

F - T = m*a 820t - T = m*0.7805t T = 820t - m*0.7805t I am confused what I would use as mass? Mass of cart A, or mass of cart A and tractor?

At the time of release, the equation of motion of blocks A and B T-m_ag = m_aa and T=m_b\omega^2R respectively, where T is the tension in the string. Solving for the acceleration a then gives a=\frac{m_b\omega^2R - m_ag}{m_a}. Not sure what I did wrong or what incorrect assumptions I made...

What percentage of current new research in theoretical physics is focused on string theory/M-theory/supersymmetry? Are most PhD students or tenure track researchers still working in that space or are other ideas becoming more fashionable? I assume it must be less than 10 or 20 years ago, but...

In his solution, Morin solves the problem as the hint suggests: cutting the chain into small pieces, taking the component of the external forces along the curve (which is just the component of gravity here) and summing up an in integral, obtaining 0. He then claims that because the "total...

#F= m\frac{v^2}{r} = mw^{2}r# #m=5# #r=0.9# #F= 5\frac{v^2}{0.9} = (0.9)5w^{2}# #5\frac{v^2}{0.9} = (0.9)5w^{2}# #\frac{v^2}{0.9} = (0.9)w^{2}# #v=0.9w# then I get stuck cause I have both unknowns in one equations (i bet it has something to do with the question’s use of “minimum” but I...

I saw the following problem in a test I was reviewing: I don't understand how they got their answer. I used the formula: ƒ=sqrt(T / u) / 2L where f is the frequency of the string, T is the tension, u is the linear mass density, and L is the length of the string. I got: T = mg = 50 * 9.8 = 490N...

Variables: Dependent: Vibrational frequency of violin string (Measured using mobile tuning app) Independent: Temperature in which string is plucked (Measured using infrared thermometer) Controlled: Violin String, Tension of violin string, Length of violin string, Method of plucking...

I understand that string theory has almost no testable predictions, however loop quantum gravity is an enticing candidate for only quantum gravity and it doesn't explain much of symmetry, constants, mixing angles etc in Standard model. There is obviously not enough evidence to create a full...

This wiki page offers an incomplete equation for calculating tension over a length of string. Can you please help complete the equation? https://en.wikipedia.org/wiki/String_bending It is referenced here in this thread post #23...

Or will confirm its predictions? As far as I can tell, you can only raise the bar on the energies required from the accelerator, but you cannot give an upper bound, where beyond it the theory is doomed... This isn't science... we might as well say we need infinite energies. 🙃

Here is the link to the question. https://www.khanacademy.org/science/physics/forces-Newtons-laws/Newtons-laws-of-motion/a/what-is-Newtons-second-law What is the magnitude of the force F1 ? What is the magnitude of the force F2 ? Here is my drawing I made At this step I am lost. ## ay...

Summary:: I need to loop through a number of strings replacing the numerals in them with an array element so that e.g.: flos1Field, flos2Field, flos3Field, etc. become flosAField, flosBField, flosCField. The array would be something like: const letters = ["A", "B", "C"]; I put the question in...

I am doing private studies in string theory and am reading "A first course in string theory" by Barton Zwiebach. Below equation 6.52 the author says "Since the second term on the right-hand side must vanish...". I do not understand why this term must vanish, and I would be grateful for an...

I am learning to code and 1 thing that surprises me is how do I internalize all the code? I understand the code. I know the algorithm as well. But I want to be able to solve any types of problems(related ones) after learning 1 code. How do I become able to do that? So for that I am first trying...