Questions tagged [string]
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.
1,143
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Particle dynamics (mechanics), inclined plane, pulley, two blocks [closed]
The angle between the inclined plane and the surface is α. The coefficient of friction between block 2 and the inclined plane is k. Find the ratio inequality of m1 over m2 that the system remains ...
3
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1
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Wave equation of a string fixed on both the ends
I am trying to understand the wave equation of a string fixed on both the ends, which looks like this:
$$ \frac{\partial^2 y}{\partial x^2} - \frac1{c^2}\frac{\partial^2y}{\partial t^2} - \gamma\frac{\...
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Pulley System with 2 blocks [closed]
The Problem
A massless string passing over a pulley has 2 blocks of 0.1kg and 4kg tied to its ends.
The 4kg block is on the ground and the 0.1kg block is in air.
Now, the 0.1kg block is raised to some ...
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3
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Some doubt about pulleys [closed]
The image is a question which got me thinking and a doubt ocuured, if someone could clarify it, it would be highly appreciable.
I have learned that an ideal string is inextensible and 2 particles ...
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2
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Finding the greatest distance reached above the ground [closed]
i dont understand why there is an additional 0.441 added to the final distance... i do understand that the distance travelled by A downwards is equal to the distance moved by B upwards but why the 0....
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1
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Axis of rotation of a spool unwinding and falling under gravity
There is a problem that asks for forces that apply torque around the axis of rotation on a spool of string that falls and unwinds under gravity. The spool falls straight down with a vertical string. ...
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2
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61
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The direction of net force in circular motion
The small ball attached by a thin string is in uniform circular motion as shown in the picture (vertical plane). There are two forces acting on the ball, Gravitational force $F_g$ and Tension force ...
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Tension in cord is half harmonic mean (Interpretation)
Calculate the tension ($T$), in terms of $m$, $M$ and $g$ in a cord, where an object of mass $m$ overhangs a table via a cord attached to a mass $M$. Ignore friction, and assume the cord is massless, ...
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How to measure the tension in a guitar string without directly measuring the frequency of the sound?
I'm looking for an accurate method to measure the tension in a guitar string, without using a sonometer setup nor by measuring the frequency.
the current method that I have in mind is to measure the ...
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28
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4
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How does a violin produce notes, microscopically?
I believe this question would have been asked before, but not like this. The popular answer to this question is that the slide-release action of a bow sets up vibrations in the strings, of which ...
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What is the weight read by a scale on top of an Atwood's machine?
Let's say between the ceiling and the massless, frictionless pulley is a scale. If you let go of the weights, right before they start falling, you measure the weight. I thought that because if the ...
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An acrobat of mass $m$ clings to a rope ladder hanging below a balloon of mass $M$. If the acrobat begins to climb the ladder at velocity $v$
An acrobat of mass $m$ clings to a rope ladder hanging below a balloon of mass $M$. If the acrobat begins to climb the ladder at velocity $v$. What is the speed with respect to Earth with which the ...
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2
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Tension, Centripetal force and Simple-Pendulum
At position 3
We've to find tension in the string (ideal).
The answer is:
$$ T = mg\cos\theta $$
But my doubt is, how can Tension at 3 balance the radial component of gravity.
If that were so the ...
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We have to find the acceleration of block of mass $m$ just after the system have been released from rest [closed]
I have already solved the question and my answer is coming out to be$ g(√2/3)$ but in the answer key it is only $g/3$ by not considering the horizontal motion of the block B but due to the motion of ...
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Question about the net force a rope [closed]
In a case like this one where the mass of the rope is considered to be 0 how can we prove that the net force on the rope is 0?
Using $F=ma$ I don't see how that would prove that the net force is 0.
Is ...
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What exactly is Tension Force? [duplicate]
I have been reading recently about tension. I don't exactly understand how it works. Here are my major doubts:
Here, Tension is said to be acting in the opposite direction of mg. I will assume ...
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3
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Direction of tension forces acting along a string
I have recently started studying the Tension force and came across this diagram{attached below} of tension forces on a string and am unable to comprehend that how the direction of the tension forces ...
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Do I do more work if I pull on a rope that is 1) attached to a wall or 2) attached to a movable column?
Let's say I'm standing on a frictionless floor, and there's a rope attached to a wall or movable column. I pull on the rope with a constant force. Clearly I must move towards the wall/column, so I do ...
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Shape on string for function in range $(-L,+L)$ [closed]
What combination of wave equation solution should I assume for string fixed at $x=-L$ and $x=+L$. I was trying with for example:
$$\psi_m(x,t)=\cos(k_mx+\alpha_m)[A_m\cos(\omega_mt)+B_m\sin(\omega_mt)]...
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Effective mass of pulley system [closed]
Below is the original problem:
A particle of mass $3m$ is connected by a light inextensible string passing over a smooth, fixed, pulley to a smooth pulley $P$ of mass $M$. Over this pulley passes a ...
23
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4
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Magnetic field changes induced by vibrating electric guitar string
Here is a picture (from a paper by Feinberg and Yang in the Journal of the Acoustical Society of America) of an electric guitar string vibrating (mostly in the $y$ dimension) near a permanent magnet.
...
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What happens with natural frequency on a rope which length is changing?
I was watching violin concerto, and I thought of two scenarios of sliding on the string and taking finger off the string as shown in the image:
Define $v = \sqrt{\frac{T}{\mu}} = f\lambda$, $T, \mu, ...
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Rope strength necessary to stop a fall
Just a random thought experiment, that got me confused.
So when you buy a rope you get info about Tensile Strength(lbs) or kg let's say 1000kg.
That means it can hold an object of that mass.
But the ...
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2
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2
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Solving pulley system using $\Sigma T.x=0$
I found this on the internet
Why should $\Sigma T.x=0$ hold?
Source: https://www.quora.com/How-do-I-solve-pulley-constraint-problems
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Problem relating 2 pulleys
In the image attached, why is the net force on pulley B, 0? We consider the tension in string 2 twice that of string 1 because we assume the force on B to be 0 and thus no net force on B. But what is ...
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4
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Confusing statement about tension
Website writes
The system is the tightrope walker, and the only external forces acting on him are his weight $W$ and the two tensions $T_L$ (left tension) and $T_R$ (right tension), as illustrated
...
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Pulley with mass and string [closed]
I am dealing with dynamics of a rigid body, and I can't understand the "algorithm"/problem solving approach behind solving to set equations to solve problems: I thought it was to apply ${F}_{...
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Potential energy term in lagrangian of waves on a string
I'm going through Quantum Field for the Gifted Amateur, in example 1.4, the wave equation is derived through the Lagrangian. A key fact used is that, the potential energy equation is given as:
$$ V = ...
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Why does a rope attached to a block move when pulled?
In the diagram above, person $P$ is pulling block $B$ by a massless rope $R$, and they are all accelerating in the indicated direction.
If the force that $P$ applies to $R$ is $F_{P,R}$, then to my ...
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Why should the tension be constant throughout if there is external force? [closed]
I came across a question from Pathfinder for Olympiad. The question was:
A frictionless non-conducting inextensible thread of length l wears three beads of positive charges q1 , q2 and q3. The ends of ...
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1
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Forces of an elastic closed string
I want to calculate the forces acting on an element of a closed elastic string and derive a wave equation on a closed string. For this I have already figured out that if the closed shape of the string ...
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How to create a standing wave that doesn't oscillate with the fundamental frequency?
Is there a way to make the string on my violin vibrate in an overtone frequency instead of the fundamental frequency?
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How tensions of $y$ axis are different, but overall tension still the same?
Let's say rope is at equilibrium and both ends are attached to something(boxes). We put a finger on it and let go. So it starts accelerating upwards.
Let's consider just a tiny, tiny piece of the ...
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3
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How to understand the larger than $g$ acceleration of the free end of a falling chain?
In this article I read that the acceleration of the free end of a falling folded chain is greater than $g$, but I cannot really understand why. Why isn´t the acceleration just $g$ since it is a free ...
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Analysis of simple pulley system
I have some questions about the motion of the simple pulley system illustrated in the book Machinae novae. Are the following conclusion about the system correct?
Since the length of the rope is ...
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1
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What does disc sliding over a string means in this system? [closed]
I was studying Newton's Laws of Motion and my book gives a diagram in order to explain what components together can or cannot be considered a system in the figure given below.
Now it says we cannot ...
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An elementary question on blocks and string [closed]
I have a doubt in one of the problems, I came across in a book.
Though I searched answers for it, I was not able to develop a satisfactory understanding.
The question asks us to draw a free body ...
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What is actually the clear, precise and world-wide accepted definition of TENSION FORCE?
This is a long post, but only because I have explained the scenario very very clearly,90 percent of this post is explaining you a simple situation,my doubt is only 5-6 lines at the very end of this ...
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4
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What is the reaction force when I "push" a string/rope/wire of some mass $M$?
Consider a situation like this
There is a rope of uniform mass $M$ whose one end is attached to a wall.
Obviously, the gravitational force $mg$ and normal force are acting on it in vertical direction ...
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Tension in a violin string
Say we have a string of fixed size on a violin. If I were to play it open (without pressing down on it) it would vibrate at a certain frequency. If I were to play it whilst pressing down on the middle,...
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(Physics 2, Waves) Why does $\tan(\theta) = dy/dx$? [closed]
In the following example:
At the very last step, how does the author get that $\tan(\theta) = dy/dx$? To which $dy$ and $dx$ is this referring to? It can't be the same $dx$ that is labelled in the ...
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3
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Why In the below diagram, the force causing torque on disc is $T$ not $T+mg$?
please see the image attached, I have to calculate torque acting on the disc, and my teacher took the force causing torque T not T +mg, I think it should be T +mg because that block is also exerting ...
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Normal contact force, friction
If two blocks are resting on top of each other and are on the ground, the weight of the upper block causes an equal and opposite reaction force on the lower one (Newt 3rd) and the same happens for the ...
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Relation between frequency of vibrator generator and frequency of waves in a stretched string
Imagine a vibration generator is attached to a stretched string. Will the frequency of the vibration generator be equal to the frequency of the waves produced in the stretched string?
Also, a similar ...
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Change in kinetic energy of mass pulley system [closed]
Imagine a pulley (with non-negligible mass) with two masses hanging from the pulley on a rope on opposite sides. One mass is accelerating downward and the other mass is accelerating upward. We assume ...
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$F=\frac{dp}{dt}$ for falling chain [closed]
There are several questions on Physics SE regarding the problem of a falling chain. However, to the best of my knowledge, no one has yet asked the following one. Consider the scenario presented in ...
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Why does a Foucault pendulum need to swing?
Let's imagine a Foucault pendulum placed at the North pole of the Earth.
If it is oscillating, we know that the plane of the oscillation will stay fixed with respect to distant stars while it would ...
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Why is the work done by the tension in a pendulum string zero?
Isn't the string pulling the ball upwards, and, therefore, doing work on the ball, like when someone lifts weights. I understand that the force is perpendicular but can I get an intuitive answer as to ...
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Does Hooke's Law apply to all springs?
I understand that Hooke's Law is $F=-kx$, and that this law only applies when a spring is not "overstreched." However, does Hooke's Law apply to all springs, or only simple harmonic ...
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Higher-order helical structure of twisted string
Why does twisting a right circular cylindrical, small-radius string around its axis eventually cause it to develop higher-order helical structure? When does the transition to this structure begin and ...
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