Waves are disturbances that propagate through space and time. Classically, they travelled through a medium, disturbing the particles but not changing their mean position. Electromagnetic waves/particle-waves need no medium; they are disturbances in their respective fields.

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Inverse of the D’Alembert wave operator

Let $f(x)$ a solution of the wave equation $\square f(x) = 0$. I don't understand why the following operator $$ \mathcal{D} \equiv \frac{1}{2}(\nabla^2)^{-1} (x_0\partial_0 - C) $$ for arbitrary ...
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60 views

Is there a consensus on the definition of wavelength for a solitary wave?

Solitary waves are by definition a wave of single nature so the usual definition for periodic waves does not apply. R. Dalrymple provides a definition but I saw a lot of other websites and papers ...
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85 views

What could be the distribution of an explosion energy of a mining-grade and seismic exploration explosives?

Seismic exploration involves the excitation of seismic waves using the industrially made explosive charges. What could be the distribution of explosion energy of such a charges? My guess is that it ...
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76 views

What is the physical meaning of group velocity for elastic waves through crystals?

In a chapter about phonons they define group speeds for elastic waves in crystals as the derivative of the dispersion relation: $$v_g = \frac{d{\omega}}{d{k}} $$ I wonder though how they come to ...
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41 views

I've been reading that it's possible to create a “mostly magnetic” wave, and I have a few questions

Would it be possible with the "mostly magnetic wave" to have it behave in such a way that it would be undetectable by radio triangulation? I read about the monument at the CIA headquarters that was ...
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194 views

Standing Waves in Flutes

How do the waves produced in flutes have a wave characteristic while maintaining a velocity that allows them to travel to out ear? If it were simply a standing wave I'd imagine that they would ...
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105 views

Longitudinal EMAG wave?

I'm reading about optical waveguide analysis, and often come across the terms "transverse electric mode" vs. "transverse magnetic mode". As I unerstand, it means that the electric/magnetic field has ...
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128 views

How do you super impose two or more signals to occupy a fix area of space with the resultant summed wave?

Is it possible to super-impose two or more signals all sent from different directions as a standing wave with the resulting summed wave occupying a fix area of space that is also a complex area? Do ...
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69 views

What phenomenon is responsible for the evolution pattern of waves created by waterfalls?

I have been fascinated lately by the pattern of the waves created by a waterfall in my town. Specifically, the pattern shows a gradual decrease in the density of the waves as they travel away from ...
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154 views

Behavior of wave at boundary

Firstly, how is "density" of wave formulated as? Secondly, when wave, travelling in less density medium, meets with the boundary that has higher density medium next to, reflected parts of the wave ...
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197 views

How to derive a multi-reflection echo from a given single-reflection “trace”

Consider a one-dimensional semi-bounded "ray" (or thin "cylinder") of stratum (or just any homogeneous substance) which has several "features" along it's length (say, thin films). Consider a wave that ...
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448 views

Depth of sea and point at which waves break

Following up on this answer, is the point at which waves break on the sea shore a guide to the depth of the sea at that point? Could it indicate eg hidden rocks? Explain the direction of waves on sea ...
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140 views

Reflected electromagnetic wave relation

If incident electromagnetic wave is given as: $$\begin{align*}E_i&=A_e \cos(\omega t + bz)\\ H_i&=A_h \cos(\omega t + bz)\end{align*}$$ What would be relation for REFLECTED wave? Does it ...
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68 views

Reorienting a sensor axes according to particle displacement directions

Consider a sensor which is located inside the solid substance. This sensor is capable of detecting the substance oscillations along each of the three axes (usually orthogonal, but generally, any ...
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19 views

Waves and (Another) Question about the Double Slit Experiment

Apologies for posting yet another question about the Double Slit Experiment, however, there are a couple of things I wouldn't mind clearing up (if possible!). I don't really have much of a background ...
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22 views

Wave equations for reflected waves in standing wave calculations, when the end is fixed and when it is free?

Consider a sinusoidal wave moving in the +x direction $$y_{1}(x,t)=A\sin\left [ \frac{2\pi }{T} \left ( t-\frac{x}{v} \right )\right ]$$ (A) At a fixed end, the amplitude of the resultant wave ...
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19 views

Time for water wave to reflect

In class we discussed an experiment for measuring the speed of waves in water. The basic procedure went something like this: Make a wave at the near end of the tank and wait for it to travel to the ...
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7 views

Solution for elastic wave on plane of ideal contact between two half spaces of elastic, homogeneous, isotropic, linear solids

Please give the solution for elastic wave of arbitrary polarization incident at arbitrary angle on plane of ideal contact (meaning no slip, homothermal, nondissipative, and no transfer of material ...
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6 views

Zero stress boundary conditions for the acoustic wave function

When is it appropriate to use zero normal stress boundary conditions when solving the acoustic wave equation. That is when the pressure is equal to zero.
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25 views

Refractive index and electric susceptibility

Suppose we have a complex refractive index $n_{ref}=n+ik$ whose value is given at a precise frequency $\omega_l$ from experimental data. We know that the imaginary part is responsible for the ...
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13 views

Formation of standing waves in a flume

Having observed standing waves in a flume when the Froude number > 1, I'm unsure how they form at this flow speed. My understanding of standing waves is that it requires equal waves traveling in ...
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47 views

General solution of the four-vector with each component satisfying the wave-equation

Maybe this is more appropriate for Math stackexchange, but this question regards the solution we use in order to find representation for massive / massless spin-1 particle. When $$(\Box + m^2)A_\mu = ...
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28 views

What does invariant exactly mean and how does it get the invariant?

I have read many journal about simulation of regularized long wave. In numerical test section,many researcher use invariant of mass,momentum and energy to check accuracy of their method but i found ...
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20 views

standing wave formation in a string of varying density

What will be the condition of standing wave formation in a string fixed at both end if density of string is uniformly increasing ?
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24 views

ratio between conduction current and displacement current

First, recall that Maxwell displacement current for a plane wave is $$ \vec j_D = \epsilon \partial_t \vec E = \epsilon \partial_t (\vec E_o cos(\vec k \cdot \vec r - \omega t)) = \epsilon \omega ...
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25 views

Does superposition principle apply to the velocity of each particle in a wave?

Superposition principle can be applied to find the net displacement of a particle when two waves interfere. But can it be applied in case of velocity? If so, then what happens to the velocity of the ...
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18 views

Can a patterned microwave beam with alternating frequencies be created?

Is there a way to create a patterned microwave beam with alternating frequencies such that, in the far field, from top to bottom of beam, there is repeated pattern of Wavelength one, Wavelength two, ...
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52 views

Derivation of group velocity?

In the standard simplified derivation of group velocity (which can be found here) we use two waves $$y_1=A\sin(K_1x-\omega_1 t)$$ $$y_2=A\sin(K_2x-\omega_2 t)$$ In the proof we then get ...
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83 views

What happens to the velocity distribution during constructive interference?

Two pulses(one inverted & having velocity in the opposite direction) moving towards each other with same wavelength & amplitude after undergoing destructive interference do reapper. Why? ...
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37 views

In Young's double slit experiment how can we determine the shape of fringes formed?

Does the shape of fringe change if the type of source is changed (point source or extended source) or if the relative position of slits is changed (both lie on a line either horizontal or vertical to ...
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13 views

how to measure the wave emitted from some particles after input sine wave into the particle

which waves can be input into the particle? is it sine wave? is the wave emitted from the particle after input wave into the particle different? if want to measure the output wave, how to use math ...
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39 views

How much energy and momentum is carried by a mechanical wave?

Let's assume there is a wave spreading across in a substance. Described by some partial differential equation. How can I calculate the momentum and energy carried by this wave? Or maybe the energy and ...
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22 views

Is the oscillation of all particles for stationary wave equal?

Is the oscillation of all particles for stationary wave equal? I think the point of nodes for stationary wave never oscilliate. Is this idea true?
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6 views

Acoustics - Phased Arrays

Has any work been done on phased arrays of speakers and microphones on the walls of a house being used to; * create maximas of ultrasonic waves at a given point in a room. * software to ...
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15 views

Pressure evolution equation atmosphere

Working on gravito-acoustic wave propagation in a windy and viscous atmosphere I tried to recover the pressure evolution equation. My starting point was the adiabatic state equation : ...
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75 views

Wavefront of a wave?

I'm trying to understand the idea behind a wavefront in a visual manner. Take a look at these surface waves in water Now imagine if I sliced it twice, through the origin, in a vertical plane. I'd get ...
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47 views

Huygens and philosophy of the slit

A single (narrow) slit diffraction pattern, can be explained/described classically with Huygens' principle (1678), and quantum mechanically with the Uncertainty principle. If the pattern on the screen ...
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43 views

The amplitude of oscillations in sound waves

How can the amplitude of molecules displacement be measured in a sound wave? How can the amplitude of the pressure fluctuation be measured in a sound wave? What are the difference between these two ...
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67 views

What affects the period and the frequency of a longitudinal vibration?

In a lab experiment, our objective is to observe the characteristics of longitudinal waves/vibrations. If we changed the mass and amplitude, I feel that they either affect the period and frequency of ...
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14 views

Comparing the Intensity of a Point on the Screen to the Central Max (Double Slit Experiment)

For (b), I know that the following equation will give me the ratio of the intensities: $cos^2(\frac{dsin(\theta)\pi}{\lambda})$ I do understand the theoretical basis behind the formula. However, ...
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18 views

How can water waves be transverse when we know that transverse waves are not possible in fluids?

It is said that fluid cannot sustain shear stress so a transverse wave cannot exist in fluids. Well, isn't this contradictory to what see we everyday in the form of water waves?
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73 views

Amplitude resonance

Why does amplitude resonance occur at a frequency lower than the natural frequency of a body? specifically, why is $w=\sqrt{w_0^2-2a^2}$ where $a=\frac{damping\space force}{2\cdot mass}$
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38 views

Electric Field Inside Dielectric Filled Cavity

I want to determine the electric and magnetic fields inside the following cavity: perfect conducting walls at $z = 0, z=d, x=0, x=b, y=t, -t^\prime$, with a dielectric $\epsilon$ filling ...
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60 views

How can Young's double slit experiment explain the wave nature of light?

I've been reading about wave theory of light and the famous experiment performed by Thomas Young. But how does this experiment prove that light is a wave ?
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116 views

Relation between size of obstacle, wavelength and diffraction

"If the boundary is merely an obstacle implanted within the medium, and if the dimensions of the obstacle are smaller than the wavelength of the wave, then there will be very noticeable diffraction of ...
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26 views

What equation can be used to solve an ideal string/membrane in a non-vacuum medium?

I'm interested in the eigenmodes of the membrane for various mediums, such as vacuum, air, water, etc., which impose a damping effect on the membrane. This cannot be done by merely changing the value ...
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28 views

Can radial mode standing waves exist in a column of gas?

In a solid bar such as aluminum one can excite transverse, longitudinal and torsional standing waves. In a column of gas bound within a tube, whether open-open, open-closed or closed-closed, physics ...
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28 views

Sound vibrations for marine propulsion

I asked a similar question about bubbles making less friction on a mass moving through water, now I'm wondering of sound waves could do the same thing as supercavitation or possibly create it's own ...
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48 views

Standing waves on a compound string

I've been having some difficulties in understanding standing waves. The questions that I have are as follows: 1) Suppose I have a compound string, made up of two strings. What is the correct way to ...
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144 views

Destructive and Constructive Interference Sign Problems in Sound Speakers

The problem statement, all variables and given/known data Problem b). Looking at the attached document of my teacher, the visual representation of the answer does make sense. Relevant equations ...