# Tagged Questions

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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### Acceleration of a pulley system

The figure above shows a pulley system consisting of 3 masses ($m_1$, $m_2$ and $m_3$), a homogeneous wheel (radius R, mass M) and 2 massless pulleyes which are connected by a massless rope. Mass $m_1$...
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### Particle attached in equilibrium to two elastic strings

The question I'm trying to answer is this: This is the solution: The only part of the solution I have a problem with is $x_{ps} + x_{qs}=l$, where $x_{ps}$ is the extension of the string from $P$ ...
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### Harmonic frequencies of a guitar string

I'm studying harmonic frequency at the moment but I'm just a bit confused about something. How are more than one different frequencies able to be produced from plucking a guitar string (fundamental ...
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### standing waves on a string [closed]

I've a problem that I can't solve, could someone please help me? The problem says: Two strings of a bass vibrate in a normal oscillation mode with the same period of 8.0 milliseconds. If the ...
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### Why are the harmonics of a piano tone not multiples of the base frequency?

I was trying to figure out which piano keys were being played in an audio recording using spectral analysis, and I noticed that the harmonics are not integer multiple of the base note. What is the ...
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### Can we know the tension of the string that is connected to a pully?

If the pulley have mass, I learned that T1 and T2 isn't same. then what about the circled part of the string? can we calculate the tension with given T1 and T2?
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### Conceptual doubt in Tension force

I recently studied that Tension in a string is a kind of force originated from electrostatic attraction between the atoms of the string in which the force is originating. My doubt was that: Assume ...
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### Standing waves on compound string

Please help with this question - No data is given as such. The 2 strings have different thickness. Initially, minimum frequency of the thick string is 120 Hz. Then if we push the cart such that only ...
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### Springs acting on a car [closed]

I am trying to solve a problem but I can't figure out why the answer comes out to be what it is: A man of 80kg enters a car and compresses the 4 springs of the car, causing a change of 1,2cm from ...
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### Vibrations of a string [closed]

A string with length $L$ is stretched between two fixed points. The string can't vibrate with which wavelength? Four options are given, namely $L$, $L/2$ , $2L$ and $4L$. I know that the ...
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### Tension in a string with pulley and two objects at opposite ends

Tension is confusing me. According to my understanding of tension the tension in a string is uniform but while going through the solution of a problem I read that tge tension on the left part of the ...
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### Question on the constraint force of a string

I would like to know if the following statement is true or false even if I expect that it is true. Notation: I will consider a string that has no mass and that can not be extended. Saying that a ...
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### Accelerations of Cylinders

I got a box hanging from a rope that passes through an ideal pulley that attaches to the superior part of a Cilynder and makes it rotate. An exercise asks me two things: a) determine the magnitude of ...
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### Momentum of transverse waves on a string

In general, if a wave carries energy density $u$ with velocity $v$, it also carries momentum density $u/v$. I've seen this explicitly shown for electromagnetic waves and (longitudinal) sound waves. ...
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### How does string tension influence the harmonic spectrum?

Hey there fellow physicists & musicians! I have a question both physics and music related. How does the string tension affect the sound spectrum? More precisely, how do the respective ...
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### Vertical circular motion/How can tension be negative?

This is a rock tied to a string spinning vertically. Here, $T+mgsin\theta = mv_1^2/r => T = mv_1^2/r-mgsin\theta$ Suppose I give it a velocity $v$ at the bottom. 1) At what angle $\theta$ will ...
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### Astronauts on a tether

Recently, I went to a competition with a science test. One of the questions was as follows: Two astronauts (A and B) are tethered together in space. Simultaneously, Astronaut A pulls on the tether ...
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### Are mechanical energy of an element of a rope and energy density constant in the case of mechanical waves?

I'm confused about energy driven by a wave. Consider a sinousoidal wave moving in a rope. In my view each element $dm$ of the rope follows a simple harmonic motion in time. That means that the ...
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I'm studying stationary waves on a rope fixed at both sides. In some books I find that the wave function studied is the sum of incident wave $\xi_1(x,t)$ and of the reflected wave $\xi_2(x,t)$. $$\xi(... 1answer 29 views ### Is it possible to have two waves of different frequency on one string? Would this change for different Hz, Wavelengths, Speeds, or amplitudes? 2answers 62 views ### Pseudo force/negative acceleration The goal is to find \boldsymbol {a_0} I already have the solution, however, I have a few questions. In the solution they have taken \boldsymbol {m_2}'s acceleration relative to the ground to be ... 0answers 12 views ### Pulley Advanced Equilibrium Problem [duplicate] How to show that M would have to be more than 8m 0answers 23 views ### Will the force acting be doubled? [duplicate] If me and a man are holding a string, and I apply a force of 100N, the tension in the string would be 100N, and it would exert a 100N force on the man and an equal and opposite force of 100N on me. ... 1answer 60 views ### Plucking Guitar Strings [closed] 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 ... 3answers 93 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, ... 1answer 81 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, ... 3answers 135 views ### Transverse Wave [closed] Tranverse Wave is travelling in a string. 2answers 181 views ### 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 ... 2answers 50 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 ... 1answer 43 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 ... 2answers 148 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? 1answer 33 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? 2answers 68 views ### Spring pulley system Hey can someone please help me with this question, the answer given is B and C, but my doubt is that the acceleration of both the masses should not be the same and K_1x_1 = K_2x_2 ...[equation 1] ... 1answer 100 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 ... 1answer 34 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 ... 2answers 56 views ### Torque and a pulley I'm supposed to find, symbolically, what the moment of inertia of the pulley is using T_1, T_2, r, and a. Obviously the base equation would be the sum of the torques equals Iα. I have the ... 1answer 49 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 ... 1answer 42 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 ... 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 ... 2answers 57 views ### Why the earphones in the pocket always form knots? How to explain this problem in Maths? [duplicate] And how to build a model to study of it? 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 ... 0answers 32 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 ... 1answer 46 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 ... 2answers 100 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 ... 4answers 113 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 ... 1answer 62 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 ... 2answers 67 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, ...
In the following diagram, what's the force that's acting on $m$, the Tension in the string? There is no friction between $M$ and the ground but there is between $m$ and $M$ and I need to find the ...