This tag is for non-relativistic material strings, such as, e.g., a guitar string. PLEASE DO NOT USE THIS TAG for relativistic strings and string theory.

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-2
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0answers
35 views

What is $T_1$ and what is $T_2$ in Capstan law? [on hold]

How do I determine which force is which (T1 or T2) in the Capstan law? In case there is no rotation and in case there is rotation of the capstan.
1
vote
0answers
47 views

Plucking Guitar Strings [on hold]

I was given this prompt: A musician frets a guitar string of length 1.5 m at x = 0.28 m with one finger, and simultaneously plucks the string at x = 0.14 m with another finger (raising it to a height ...
1
vote
3answers
75 views

What is the physical meaning of reduced mass?

If we stick two block masses by a string and pass it over a pully and let the blocks free then mathematically we can obtain that the whole weight on the pully is more if the blocks are kept at rest, ...
3
votes
2answers
59 views

What happens if I slowly lower a dangling object into a black hole?

I could've sworn I've seen this question before, but I couldn't find it. Suppose I have an object on the end of a really long string. I can slowly lower it near the event horizon of a black hole, ...
6
votes
3answers
96 views

Transverse simple harmonic wave travelling in a string [on hold]

This question came in my exam. My Attempt: I thought that the tension will not vary in the string because since we know that velocity of wave in a string is given by $$v=(T/m)^{1/2} $$ where $v$ ...
8
votes
1answer
60 views
+50

Rope waves with a twist

In the picture you see a person walking a slackline. A slackline is a tensioned flatband of polyester. Typical tensions are between 1 kN to 15 kN depending on the length of the line. The lines are ...
0
votes
2answers
38 views

Force on a Massless String

Suppose we are just pulling a block with the help of a string which is massless. Now since the mass of the string is 0 the force exerted by us is transmitted without being diminished. So the equation ...
2
votes
0answers
19 views

Which supersymmetry principles make the axio-dilaton field in F-theory holomorphic?

I am following the lecture notes on F-theory by T. Weigand . On page 7 he states that when considering F-theory as the strong coupling limit of type IIB orientifolds with D-branes, the axio-dilaton ...
0
votes
0answers
23 views

How are the tension and acceleration of various strings and masses related in a system having more than two pulleys and more than two masses? [closed]

On what factor does the tension acting in a string depends if all the pulleys in the system are considered to be massless?
0
votes
1answer
31 views

Conservation of Angular Momentum for an Object Not Rotating

I have a point mass connected to a string with negligible mass. The point mass has mass $m$ and is moving at a velocity $V$. The string is of length $r$, and it is keeping the point mass tied to a ...
4
votes
1answer
78 views

Why do headphones tangle themselves whereas shoe laces untie themselves?

Why do headphones tangle themselves whereas shoe laces untangle or untie themselves? Why aren't we using the phenomenon to create headphones that tangle less and shoe laces that untie less?
0
votes
1answer
26 views

Pulley inertia momentum of inertia

Considering a pulley with some mass, or some friction, How can its inertia (or momentum of inertia) influence the tension on 1 rope? Which part of the rope is influenced? Before or after the pulley?
0
votes
1answer
79 views

Atwood's Machine [closed]

Using an Atwood’s machine, how will the acceleration change if the sum of the two unequal masses (total mass) are kept constant while the mass difference changes? Using an Atwood’s machine, how will ...
1
vote
1answer
87 views

Spinning a string with a mass on the end. What makes the mass rotate parallel to the ground? [closed]

Say you use your hand to rotate a string with a mass attached to the end. The string will first become taunt and then the mass and string will move upwards until they are spinning parallel to the ...
0
votes
1answer
28 views

Rope tension definition

What is the exact definition of the tension of a rope? Here http://web.mit.edu/8.01t/www/materials/modules/chapter08.pdf the following definition is given The tension $T(x)$ in a rope at a ...
0
votes
0answers
26 views

Ramond-Ramond potential and field strenght

I have a doubt about R-R potential in Superstring theory. The known facts are (according many books, for example "Basic Concepts in String Theory" by R. Blumenhagen, D. Lüst and S. Theisen): in the ...
0
votes
1answer
45 views

What's the required tensile strength for a wire?

I want to horizontally stretch a 50 meters wire rope and slide 100 kg object from side to side. What should be the minimum tensile strength (or carrying capacity) of the rope to be able to hold the ...
3
votes
1answer
30 views

Slackline tangling

This question is about random formation of knots in a systematically tied rope. I will give some background, hope that does not make it off-topic. In climbing (and sailing) one has to store very long ...
4
votes
4answers
1k views

What Keeps a Pendulum Moving In a Circular Path?

From the figure, we know that $F_{net} = mg\sin\theta$. Now, this force $\vec{F_{net}}$ is in the direction of the velocity $\vec{v}$ of the bob, both are tangent to the path. Therefore, the net ...
3
votes
2answers
48 views
10
votes
2answers
1k views

How can you make harmonics on a string? [duplicate]

For an oscillating string that is clamped at both ends (I am thinking of a guitar string specifically) there will be a standing wave with specific nodes and anti-nodes at defined $x$ positions. I ...
1
vote
0answers
26 views

Standing Waves in a String of two Linear Densities

Given a string with sections of two linear densities like this: Does the point where the two linear densities meet have to be a node if a standing wave is produced? Are there alternatives? Could I ...
1
vote
1answer
32 views

Dependence of tension (considering a pulley system) on the mass of loads

Consider the diagram below All circles are pulleys, which are fixed at the ceiling. M represents an engine (with a certain power) that is pulling the cable. C and D are weights. The acceleration of ...
1
vote
2answers
47 views

Condition for looping the loop

Consider a ball tied to a string and it is imparted a velocity we have studied that condition for looping the loop is that tension at the uppermost point must be zero, but why is this condition ...
1
vote
4answers
86 views

When is tension positive?

A 5kg mass is hanging from the roof of an elevator accelerating downward at a speed of 1.65 m/s^2 what is the tension of the string (ignore friction, string mass, and air resistance) ? I used this ...
0
votes
1answer
44 views

Finding mass attached to the string

I'm given the following problem: One end of a string with a linear mass density of 7.60* 10^-4 is connected to an oscillator with a frequency of 50.0 Hz. The other end is connected to a hanging ...
3
votes
2answers
64 views

shape formed by a stiff string with ends pinched together [closed]

Suppose I have a string of length $L$ with a bending energy given by $$E=\frac{1}{2}\epsilon \int_0^L ds\, (\mathbf{R}''(s))^2 $$ Let's say I form a bight with it by pinching the ends together, ...
0
votes
3answers
63 views

Conditions for the tension to vary in the rope

What are the conditions for the tension to vary in the rope. I have read below conditions 1. rope has to have some mass 2. rope is accelerating I get the 1st ...
1
vote
1answer
71 views

Normal Ordering in String Theory: Polchinsky vs. all others

Polchinsky defines normal ordering in string theory as: $$:X^\mu(z,\bar z)X^\nu(w,\bar w): = X^\mu(z,\bar z) X^\nu(w, \bar w) + \frac{\alpha'}{2} \eta^{\mu\nu} \log |z-w|^2$$ and for more ...
0
votes
1answer
42 views

Tension in a vibrating loop

Consider a super basic 1D vibrating string, with standing waves on it. The string has length $L$, and the wave propagates at a velocity $v$. The fundamental frequency $f_1$ is given by $$f_1 = ...
1
vote
2answers
92 views

Why can we assume, when dealing with tension, that the mass of a rope is $0$ but still assume that there are forces on it?

I started studying tension and I can't understand the following concept: If I have two objects $A,B$ collegated by a rope, where $A$ applies a certain force $\vec{F}$ on it, I would have that the ...
0
votes
0answers
39 views

Interpreting solution of the 1-D wave equation (vibrating string)

An ideally flexible string of length $x=L$ vibrating in one dimension ($xy$ plane) in the absence of gravity obeys the wave equation \begin{equation} \dfrac{\partial^2 y}{\partial t^2} = c^2 ...
0
votes
0answers
36 views

How was the “vibrating string” studied?

The vibrating string is used to derive a lot of theory regarding strings, such as the theory about harmonics. However, since the string movement and specifically the phenomenon of harmonics seems ...
1
vote
2answers
45 views

Tension at topmost point of a vertical circle

I read that for a body to move in a vertical circle, the minimum tension needed is 0 at the topmost point. Can someone explain to me what it means to have positive or negative tension on top. I'm not ...
0
votes
1answer
79 views

Ball suspended on elastic string (finding tension)

A ball (of mass $m$) is suspended by an elastic string. It accelerates upwards with an acceleration $a$. Find the tension in the string. Taking upwards as positive, we have $$T - mg = ma \iff T = ...
0
votes
2answers
97 views

Few questions related to Tension

I am struggling with the concept of tension in a rope. Below specific questions. I am understanding tension to be an elastic force between rope molecules. If so, is it fair to say the net tension ...
0
votes
0answers
40 views

Classical string as a limit case of elastic quantum states superposition

The usuall way to "half-popularly" show that the quantum mechanics formalism is not unconnected to the classical mechanics is to demonstrate a classical case as a limit of a quantum case. The main ...
0
votes
2answers
216 views

Vibrating string, free end boundary condition

When discussing the vibrating string problem with one end (or both) free to move in the vertical direction but constrained in the longitudinal direction (achieved by placing the "free" end in a ...
1
vote
1answer
45 views

Boundary behaviour of a mechanical wave

Let us assume we have a taut rope and I introduce a pulse in it by whipping one end. Now if instead of a clamp, I have tied the other end of the rope to a denser rope, a part of the energy is ...
1
vote
1answer
90 views

An intuitive explanation regarding propagation of mechanical waves

I was studying mechanical waves today and have questions regarding how a pulse is propagated on a string and its reflection and transmission at a boundary and I hope I can find help here. First, ...
0
votes
2answers
91 views

Magnitude of tension in a bent string

I understand tension in a straight string as a reaction force to a weight, which acts along the string, ultimately resulting from the attractive forces between the constituent particles of the string. ...
1
vote
1answer
371 views

Tension in string question [closed]

Problem: A 12.0-kg box resting on a horizontal, frictionless surface is attached to a 5.00-kg weight by a thin, light wire that passes without slippage over a frictionless pulley (the figure ...
0
votes
1answer
60 views

Problem in constraint equations

In this, if I want the acceleration constraint between $M$ and $2M$, I write $AM+2AB$=LENGTH OF STRING, which on differentiating twice gives $a_{m}=2a_{2m}$(which turns out to be correct). However, ...
1
vote
3answers
156 views

Simple harmonic motion versus oscillations

I want to see whether certain oscillations in my daily life, such as the oscillation of violin strings when plucked, are simple harmonic motion or not. Can we identify whether an oscillation is simple ...
1
vote
1answer
295 views

Tension of a string, based on Hz, string-weight and string-length [closed]

I’m not a physics student. Instead I have an electric bass guitar :) I know my strings vibrating-length: 0.800 Meter I know the total weight of this length: 0.016575 Kilo I know my strings resonant ...
0
votes
1answer
84 views

Motion of string fixed at both ends

I was reading about the Fourier analysis from Waves by Frank S Crawford Jr. But I got trapped at the very beginning; this is the excerpt that troubled me: Motion of string fixed at both ends. ...
0
votes
1answer
62 views

Why, intuitively, are tension forces the same but opposite in a taut rope/string?

I'm having a little trouble understanding why conceptually the two oppose each other with equal magnitudes. Let's say you have two people playing tug of war, with person A on the left much stronger ...
2
votes
0answers
39 views

Speed of breaking (guitar) string

As I was playing the guitar yesterday, one of the strings broke and injured one of my fingers lightly. Astonished by the power of a breaking string, I was wondering whether there is a way to ...
0
votes
1answer
79 views

What's the relationship between the tension of string and the decay rate of its vibrations?

It seems that the more tension on the string, the more slowly the sound would decay after being plucked. Is there a formula relating the two? How is it derived?
0
votes
2answers
436 views

Tension in rope between falling objects

I got a mass m connected with a rope to a mass 2m which is centered directly underneat it. The masses are falling with a constant speed v. Would it be correct to say that the tension in the string is ...