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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Why is root mean square pressure used in the definition of sound pressure level?

I dont understand the way we measure loudness. I know that it is in some way related to the magnitude of pressure variations. please help me figure out where my understanding fails. Let $p(t)$ be the ...
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2answers
114 views

Why invariance holds for the electromagnetic waves but not for the mechanical waves?

Why the electromagnetic wave equation provides a wave with constant speed in all reference frames, but the mechanical elastic wave equation (from linear elasticity) does not? The electromagnetic wave ...
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1answer
56 views

Why does compton scattering provide evidence for the particle nature of light?

I understand that compton scattering is modeled as a collision between a photon and an electron, but why does this conclusively prove that light can act as a particle? Why couldn't the same ...
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78 views

Can a system be engineered to cause a standing wave resonance with gravity waves? [closed]

Thank you Docscience for helping me adjust my question in a better direction. My interest has been sparked by getting Into the chapter of waves in physics class and of course the new discovery of ...
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1answer
39 views

phase difference of two reflected wave

Suppose a tuning fork generates sound waves with a frequency of 100 Hz. The waves travel in opposite directions along a hallway, are reflected by end walls, and return. The hallway is 47.0 m long and ...
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37 views

Formation of traveling waves

can a traveling wave exist on a closed cylindrical string? or more general, what are the conditions for the formation of traveling waves vs the conditions for the formation of standing waves?
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124 views

Does sound waves pick up the speed of its source?

I googled the speed of sound and found that it only depends on the medium (just like the speed of light but with different parameters). I can't see how it doesn't pick up the speed of its source! I ...
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0answers
11 views

Draw the way the longitudinal wave spreads [duplicate]

Draw the way longitudinal wave spreads. I know how to draw how the transverse wave is spread http://picasaweb.google.com/102071315138065861533/February162016#6251906804992968450 Could you do the same ...
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1answer
32 views

Relation between the direction of propogation of sound and loudspeaker's diameter

Sound waves from a conical loudspeaker spread nearly uniformly in all directions if the wavelength of the sound is much larger than the diameter of the loudspeaker. Sound is essentially ...
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1answer
89 views

Can $Ae^{-bt^2}\sin(kx-\omega t)$ be considered a wave?

The damped wave PDE can have an exponential term, but the argument for the exponential term cannot be quadratic, AFAIK. $Ae^{-bt^2}\sin(kx-\omega t)$ So this isn't a solution for the damped wave ...
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51 views

Is there an instrument that measures the Frequency of light directly

Is there an instrument that measures the frequency of light DIRECTLY? By "DIRECTLY" I mean without using any properties of the Wavelength.
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42 views

Gravitational waves parallel

Just an idea to illustrate the gravitational waves. This kind of analogy is proposed: When you have a rotational motion of the fluid, some small amount of the energy is radiated as a pressure ...
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85 views

Non-standard representation of the free electromagnetic plane wave

The usual representation of a free electromagnetic wave in vacuum looks like this: The blue parts are the local electric field, while the green parts are the local magnetic field. The circularly ...
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52 views

Moving an object in hand back and forth creates a gravitational wave?

Does moving an object in one's hand back and forth create a wave? It creates a changing gravitation field and that propagates as a wave, right? How does that differ from a "gravitational" wave that ...
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0answers
77 views

Reflection at a conducting surface. Why the presence of surface current would require infinite electric field at the boundary?

While I was reading about electromagnetic waves in conductor, precisely about Reflection at a conducting surface on Introduction to electrodynamics by David J. Griffiths I came across some difficulty ...
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145 views

Is gravitational wave a new category of wave?

Is gravitational wave a new category of wave? We know that there are 3 kinds of waves. Mechanical wave, Electromagnetic wave, Matter Wave. Since the theory of gravitational wave is confirmed, ...
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1answer
46 views

What is the nature of ocean waves in DEEP water? [closed]

My book says that it's both longitudinal and transverse, if yes then how?
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2answers
51 views

The image of a wall clock is to be obtained on the opposite wall 2m away by the means of a convex lens. What is the minimum focal length required? [closed]

I'm in 10th grade and this question came in my physics test. Nobody was able to answer this question correctly except my physics teacher who says that the answer is 2m. My answer is that there should ...
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0answers
51 views

Graphic analysis of sound wave acceleration

I'm working on a lab involving measuring the velocity of various sound waves, done by dropping a bowling ball with accelerometers lined up in a certain position nearby. Each accelerometer is a fixed ...
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0answers
29 views

How to tell whether a wave is coherent or not? [closed]

I know that coherency means constant phase difference,but how to figure it from equation? Are all sinusoidal waves coherent?
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66 views

phase velocity versus instantaneous velocity

I'm trying to understand the relationship between phase velocity and instantaneous velocity in relation to the vector direction. This still isn't clear to me: Wave fronts move in a direction which is ...
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2answers
100 views

At which point are gravitational waves generated when two black holes merge?

I was reading today's announcement of the gravitational waves and was wondering about this situation where there are two orbiting black holes. Did the wave come from the final merging or was it from ...
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2answers
44 views

Confusion in understanding the derivation of wave speed from Newton's Second Law

In the book 'Principles of Physics' by Resnick,Halliday and Jearl Walker,the opening para of derivation of wave speed from Newton's Second Law is such: Let us consider a symmetrical pulse moving ...
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1answer
36 views

Wave optics physics

When does monochromatic beam of light incident on a reflective surface get completely transmitted.according to the question what exactly the word transmitted means? I'm little bit confused .could you ...
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26 views

Energy and power in a travelling sinusoidal wave

This stuff is driving me crazy. Here: http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/AnalyzingWaves.htm I found that the average kinetic energy per unit length is: $$ \frac{1}{4}\mu ...
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1answer
111 views

How can a probability distribution have wavelength (de Broglie wavelength)?

The wave function described by Schrodinger's equation is interpreted as describing the probability of a particle in at any point in space, i.e. a probability distribution. Since this distribution ...
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1answer
24 views

Can a piezoelectric material only vibrate at one frequency?

Given a material X with piezoelectric properties which is used in a ultrasonic transducer, what determines the working frequency of said transducer? If hypothetically such a transducer is specified ...
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26 views

How to arrange a 3d cymatics experiment?

Various researchers have filmed levitating polystyrene using sound waves. If i were to take 3 speakers and attempt to visualize the standing wave fields formed by the three speakers, how would i do ...
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1answer
79 views

Michelson Morley experiment - why is there an interference pattern in the first place?

In descriptions of the experiment, the two arms of the interferometer have the same length. There's an interference pattern which was expected to be shifted when the system was rotated 90 degrees. But ...
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65 views

The Vectors in $v=f\lambda$

We are learning about waves in physics and I was just wondering what are the vectors and what are the scalars in this function:$$v=f\lambda$$ I know the velocity $v$ is a vector so that means that: ...
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2answers
60 views

Is the video “How to Reveal Subatomic Particles at Home”'s explanation of its experiment misleading?

https://www.youtube.com/watch?v=wN_DMMQEhfQ The video asserts that along the path of an electron or muon, a trail of condensation will appear. But from what I understand, if an electron or muon (both ...
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1answer
39 views

Is the relation c=νλ valid only for Electromagnetic waves?

What is the validity of the relation $c = \nu\lambda$? More specifically, is this equation valid only for Electromagnetic waves? I read this statement in a book, which says: de Broglie waves are ...
3
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2answers
78 views

Interpretation of Eigenvalues and Eigenvectors of an hyperbolic conservation law $\partial_t W + A \partial_x W = 0$

I read in a article dealing with a hyperbolic partial differential equations this statement : For any system of hyperbolic partial differential equations (pde), expressed as (1) ...
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15 views

theoretical echo from a point scatterer

How can I compute an echo coming back from a point scatterer? Let's say I know the excitation signal (plane wave), scatterer position, medium properties, what else do I need to see, how the echo will ...
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1answer
36 views

Why eyepiece does not resolve image formed by objective lens further?

In my book it is written that "The angular resolution of the telescope is determined by the objective of the telescope. The stars which are not resolved in the image produced by the objective cannot ...
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1answer
53 views

Will smoke affect young's double slit experiment

If smoke is present in between the screen and slit in Young's double slit experiment using laser, will there be any change in the interference pattern? Will the fringes be obtained on the screen? ...
0
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1answer
77 views

What do we mean by wavelength of any electromagnetic wave?

What do we mean by wavelength of EMW? Wavelength of oscillating electric field or the oscillating magnetic field? Or is it that both the electric and magnetic field waves have same wavelength? If ...
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0answers
22 views

Why a wave, travelling in a lighter medium, inverts upon reflection from an interface of a denser medium? [duplicate]

As exactly the title says: Why a wave, traveling in a lighter medium, inverts upon reflection from an interface of a denser medium ? What are the things that go on at the interface ?
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1answer
48 views

How does electrical energy gets converted to sound energy?

I have seen that inside headphones there is a magnet with a coil of thin wire around it. There must be longitudinal waves coming out of it that is why we can listen to audio. There must be pressure ...
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1answer
93 views

How physicists explained straight line propagation of Light thinking of light as wave? [duplicate]

To explain the fact that light travels in a straight line assuming light as a wave physicist said that it has small wavelength. So how does the small wavelength explains the property?
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3answers
138 views

Why are the closed and open ends of an organ pipe nodes and anti nodes?

Here is a diagram of a wave in an organ pipe you'll find in most physics books Waves in air are longitudinal (not traversal), so what do the curves represent? Why are the open ends always anti ...
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32 views

Voltage wave reflections in transmission line loaded by matched resistor

Suppose I have a power source, a transmission line and a resistive load all connected together and all sharing the same impedance. If I send a voltage pulse starting at the power source, traveling ...
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2answers
62 views

Is standing wave realy a wave [closed]

We know that at least the waves inside a flute or laser make resonance waves,and simply we know that a standing wave is superposition of two waves that are propagating in oposit direction,for example ...
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1answer
30 views

Gaussian profile-plane wave

Simple question: How does the following wave look like? $$ U(x,y,z,t) = U_0e^{-\frac{x^2+y^2}{2\sigma^2}}e^{ikz}e^{-i\omega t} $$ Is it a plane wave? How does this propagate in space? What is the ...
2
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2answers
192 views

Why does the frequency of a wave pulse on a string only depend on the source of the wave pulse?

I am reading wave pulse on a string and their reflection/transmission, and my book says that frequency of the pulse depends only on the source of the wave pulse. But I am unable to understand why is ...
0
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3answers
53 views

relation between amplitude and frequency of a rotating electric field [closed]

I generated a rotating electric field produced by Ex=cos(wt) Ey=cos(wt-pi/2) in x and y directions. I ran a simulation and seems only in certain amplitudes and frequencies it makes a rotating field. ...
3
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2answers
100 views

What is torsional vibration?

Specifically, what is happening physically if a metal rod experiences torsional vibration? Googling torsional vibration brings up a load of research papers, well beyond the level I'm at. I can't seem ...
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1answer
78 views

Why we cannot hear ourselves or speak in water

I've tried several times to shout when I'm inside the pool but have failed to make any sound. Nor am I able to hear anyone talking outside. Why does this happen? The frequency does not change and ...
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1answer
84 views

What is the definition of phase lag and phase difference? [closed]

What is the definition of phase lag and phase difference in waves and how are these two related? Waves have always confused me,since it is very difficult to visualize them. I have tried learning it ...
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69 views

Is this SISO (single input single output) or MIMO (multiple instead of single) system?

If I transform wave equation for vibrating string Mx′′+Cx′+Kx=b(t) in linear system using $x_1(t)=x(t)$ and $x_2(t)=x_1^{'}(t)$ vibrating string equation becomes $Md_tx_2(t)+Cx_2(t)+Kx_1(t)=b(t)$. ...