Questions tagged [vibrations]
The vibrations tag has no usage guidance.
396
questions
0
votes
0answers
42 views
I am very confused this type of question [on hold]
Why is the degree of Freedom Diatomic in High Temperature 7? I have Problem 2 Vibration, I do not think 3 Vibration should be.
4
votes
2answers
73 views
Difference between sound and high temperature [duplicate]
Though vibration is a common concept in sound and “high temperature”, the essential difference between the two is mentioned to be the way the vibration takes place. The former has vibrations that ...
1
vote
2answers
66 views
Difference between Oscillatory motion and vibratory motion
What is the difference between oscillatory motion and vibratory motion.
I have read in my book that "If the amplitude of oscillatory motion is extremely small,the motion is called vibratory motion".
...
0
votes
1answer
45 views
Frequency of longitudinal waves on a string
I recently heard the composer Ellen Fullman on her Long String Instrument, which consists of steel wires of approx. 20 m length played by rubbing/stroking the string longitudinally. Changing the ...
0
votes
1answer
43 views
Damped forced Oscillation with variable external frequency
Consider that we have the following forced vibration with an input frequency $ω(t)$ variable in time.
$$m\ddot{x}+c\dot{x}+kx = F_0 \sin{(\omega(t) t)}$$
Assuming that the solution must be a ...
1
vote
0answers
27 views
Spring oscillation model
When a spring - in real world - is extended $Xo$ from its natural position, it oscillates and eventually decreasing it's amplitude with time, comes to a stop. Is this a damped system or no? If yes how ...
0
votes
0answers
31 views
Coupled Harmonic Oscillator (Forced Vibration)
I derived two equations for a 2DOF harmonic oscillator system, declared state variable equations, and placed them into matrix form: $Ax' + Bx = C$. I have a Matlab script to determine the constants ($...
8
votes
3answers
338 views
Why choosing for prime numbers eliminates vibration?
I have read that the spokes of a car wheel are usually five because, besides other substantial reasons, five being a prime number helps to reduce vibrations.
The same also happens with the numbers of ...
0
votes
1answer
28 views
Producing harmonics of standing wave on a string at non-coprime divisions
I am currently researching the properties of producing harmonics on a vibrating string fixed at its ends (e.g. violin). Lightly touching a node at division of the string a/b will sound harmonic b iff ...
0
votes
0answers
25 views
At what rate is tension released from a plucked string (eg. guitar string)?
Tension in a plucked string (such as a guitar) dictates many of the important changes that occur in the sound of the string over time. eg. It causes a pitch bend, a change in inharmonicity, and ...
0
votes
2answers
130 views
A hypothesis based on the principle of conservation of momentum
When a ball hits a wall (ground), some quantity of its momentum must be transferred to the wall at rest. If else the ball would bounce back with the exact same speed as it did when it collided with ...
0
votes
1answer
32 views
Vibrations in Stones and Crystals [closed]
I have read studies done that indicate certain sounds can either disrupt or reinforce the molecular structure (I think this is the terminology used) of living organisms. This is based on the idea that ...
1
vote
1answer
62 views
Difference in Sound and Heat
What makes sound and heat distinct ?
The answer is said to lie in the fact that the former consists of vibration in an ordered fashion while the latter is not.
But why would ordered vibration not be ...
1
vote
2answers
112 views
Can mass be ejected from a black hole within the Schwarzschild radius?
This goes far beyond my limited knowledge regarding the physics of black holes, but my colleague told me this today:
I doubt that if I stand on the surface of a black hole - inside the
...
1
vote
1answer
89 views
Can dispersion relations be derived using Euler-Lagrange equations?
The question is long because of the demonstrations I give, but the problem is simple, so bear with me for a minute.
I am trying to derive the dispersion relation of a semi-infinite system using Euler-...
0
votes
0answers
35 views
Transverse vibration of triatomic molecule from Landau Mechanics Sec. 24
Transverse vibration of a triatomic molecule ABA which consists of two identical atom A and one another atom B such as $\mathrm{CO}_2$ is depicted in page 24 Sec. 24 Landau Mechanics.
The ...
1
vote
1answer
79 views
What are “vibrations” in a field in Quantum Field Theory (QFT)?
For example, in a 2013 article for NOVA Don Lincoln writes:
Everywhere in the universe there is a field called the electron field. A physical electron isn’t the field, but rather a localized ...
2
votes
0answers
11 views
Does putting a part under stress change its natural frequency?
It is easy to imagine how tension changes the natural frequency of a wire. Intuitively it happens with a guitar string when you bend the neck.
However, does putting a beam under stress (internal or ...
0
votes
0answers
18 views
Will a cantilever tube vibrate if fluid enters from its free end and flows into the fixed end?
For dynamics of a cantilever pipe with fluid flowing from fixed end towards free end, there are values of frequency for a threshold of flow velocity that gives unstable, stable and neutral systems, ...
0
votes
1answer
37 views
How to measure the mechanical vibration when a hammer hits a nail? [closed]
I want to know the exact location of the vibration sensor that can be placed to measure the vibrations created by a hammer hits the nail.
0
votes
0answers
18 views
Normal mode decomposition of a triangular hexagonal lattice
I was trying to understand and redo the methods used in a previous question:
Vibrational anharmonic coupling and noise-induced spontaneous symmetry breaking in a hexagonal finite mechanical lattice
...
2
votes
0answers
21 views
Physics of a catenary with sinusoidal motion at one end
If we have a catenary line with a mass per unit length of m with one end fixed and the other end moving in sinusoidal motion like $A.sin(\omega.t)$, how would I ...
0
votes
2answers
62 views
Which waves are produced during tuning fork vibration? [duplicate]
In my book, it is written that transverse waves are produced during physical motion of tuning fork. But vibration of tuning fork produces sound which are compressional in nature .
Please tell me ...
2
votes
0answers
23 views
vibration and movement of electric appliance
So, what I am thinking about here is a cooking mixer placed into a bowl which is turned on and left moving on its own. The bowl is such that it does not topple nor the mixer falls out of it.
Once the ...
2
votes
0answers
24 views
Book for electromagnetic waves and radiation
MIT course 8.03SC recommends Electromagnetic Vibrations Waves and Radiation (The MIT Press) by Bekefi and Barrett for extra reading however I am unable to find any soft copy online and its too costly ...
1
vote
1answer
64 views
Why are higher frequencies amplified less by filling a bottle with warmer water instead of colder water?
Out of curiosity I was trying to figure out what makes the sound of hot water versus cold water filling a bottle different, but I'm unable to find any explanation as to why such differences occur.
...
0
votes
2answers
63 views
The Strings have a finite size they can vibrate?
as I searched about the Strings theory I found out this explanation:
Since the strings have a finite size they can vibrate. All the known particles of nature are just different modes of vibration of ...
2
votes
2answers
47 views
What makes quartz oscillators vibrate?
I understand that the principle behind it is piezoelectricity and electrostriction (inverse piezoelectricity), but how does one make the crystal vibrate?
The only thing I can think of is using an ...
3
votes
5answers
286 views
What is the reason behind resonance?
At the technical highschool that I attend, the instructor said that the cause of resonance is that energies increase differently.
Kinetic energy increases quadratically and potential linearly, so the ...
0
votes
1answer
42 views
Heat capacity due to Phonon Vibrations
Why does the speed of sound come, in the expression of Heat capacity, from phonon vibrations?
1
vote
0answers
43 views
Faraday waves and Chladni plates
I am a High school student who's writing a research paper about Faraday waves and Chladni plates. I've been doing a lot of research on Faraday waves specifically, as there aren't many sources that can ...
0
votes
1answer
60 views
Optical and acoustic branch
Does a diatomic crystal posses both optical and acoustic branch simultaneously; Or, whether the vibration is either optical or acoustic?
1
vote
1answer
50 views
Why standing wave conditions don't include a phase difference of π
So in order to set up a standing wave on string I can set a travelling wave on it first then let this travelling wave get reflected from a fixed end and this reflected wave interferes with the ...
0
votes
1answer
51 views
What will happen to these colliding strings?
What happens when these two strings collide? Do they cancel each other out, pass through each other or interact in some way?
Thanks.
1
vote
0answers
58 views
sounds of polygonal ring chimes of metal
Suppose we have a number of rings, each of them is constructed from some mass of wrought iron or steel: each ring is a polygon, which I would like to suppose is constructed without welding (so they ...
1
vote
0answers
21 views
Error in FFT (Sectrum) analyzer Instrument
Recently I performed an experiment on finding the natural frequency of vertical cantilever. I used accelerometer and FFT analyzer instrument for measuring it. First I kept the accelerometer near the ...
3
votes
2answers
103 views
Are sinusoidal travelling waves also normal modes of vibration?
According to definition of normal modes, which says if all the different independent parts of a system vibrate at same frequency and their amplitude preserve a fixed ratio then such a motion is a ...
0
votes
1answer
34 views
Shouldn't reflection at the boundary interfere with the original wave to not give any wave?
So I have been taking a wave course, and one thing that I don't understand is how does reflection even allows normal modes of vibration. I'll try to explain my confusion:
Suppose we have a string ...
3
votes
0answers
53 views
Prove from first principles that a guitar string will vibrate at a constant frequency
From experience I am aware that a taught string will generally vibrate with a constant frequency. I wanted to prove this by considering the relation of distance from the resting position, and its ...
0
votes
2answers
51 views
Calculating the power of a pneumatic piston vibrator
I am using a pneumatically-driven piston vibrator to compact a tank filled with granular material. The intensity of the vibrator can be regulated by changing the pressure of the pressurized air fed ...
3
votes
1answer
50 views
Using two simple pendulums to estimate $g$
I know that using the period expression for a simple pendulum we can have an estimation of the acceleration of gravity $g$. I encountered the following question
One way of measuring the terrestrial ...
6
votes
3answers
155 views
Vibrating string as a dynamic system
It's known first order dynamical systems had one energy storage (example C, in RC circuits) these systems act as a filter but don't resonate, on the other hand a second order system had two energy-...
10
votes
4answers
3k views
If all harmonics are generated by plucking, how does a guitar string produce a pure frequency sound?
A guitar is a plucked instrument and it is played by plucking a string at an off-centre point fixed at two ends. In general, Fourier analysis tells that all harmonics (the resonant frequencies of the ...
9
votes
2answers
2k views
Why does a metal block make a shrill sound but not a wooden block upon hammering?
When hammered, a metal block makes a shrill sound but not a wooden block of identical shape. Is it that the wooden block vibrates with lesser frequency than the metal block? If so, why is that? Also ...
1
vote
0answers
32 views
Vibrational Question [closed]
A friend recently asked me this question, which I am not even sure how to comprehend...
Three masses are arranged at the vertices of an equilateral triangle and are connected by springs along the ...
4
votes
2answers
176 views
Human perception of temperature
I had the following thought experiment recently: Suppose we have a vibrating plate for which we can tune the amplitude and frequency of vibration, and imagine we hold a finger against the plate. For ...
0
votes
1answer
37 views
Why is the UV absorption band for molecules not a sudden transition?
From what I have read, when a molecule in solution or gas is excited, it does so from ground state, but may gain the energy for vibrational transitions as well. This would lead me to expect that there ...
16
votes
2answers
3k views
Can the vibrations from the Earth affect gravitational wave detectors?
I was very interested in gravitational wave detectors and how they work exactly. From what I know they set up two lasers with mirrors set up to cancel each other out. Then if movement is detected from ...
1
vote
0answers
36 views
Laser creating weird patterns on screen when reflected from a vibrating membrane
Me and a few friends were doing an experiment today in which we took a membrane stretched over a speaker, and a small mirror in the center of the membrane. We reflected a laser off the mirror on a ...
0
votes
0answers
19 views
Frequency modes of the rectangular shell
The shapes of three natural modes having the frequencies $w_1$, $w_2$, $w_3$ of the rectangular shell are presented in the figure. The exciting pressure $p(t)$ applied uniformly all over the one side ...
