# Tagged Questions

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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### phase, group, intantaneous, and average speed/velocity

Is it correct to say phase speed or phase velocity? I've never seen a "direction" associated with phase...only a value. I want to be sure my terminology is correct. Also, how does it relate to the ...
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### 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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### 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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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: $$\frac{1}{4}\mu ... 0answers 19 views ### complex waveforms just wondering if anyone can help me out with a expression I need to find out the phase angle of any hardmonic components present ( relative to the fundamental) of this expression v= 100SIN (100 V = ... 0answers 29 views ### Maximum speed in Simple harmonic motion [on hold] If a vertical spring block executes SHM at a frequency of 10 Hz . At the upper extreme position of the block the spring is unstretched . Then how can we find the maximum speed . I tried The ... 1answer 24 views ### How can a probability distribution have wavelength (de Broglie wavelength)? The wave function described by Schrodinger's equation is interpreted as describing the probability of a particle in at any point in space, i.e. a probability distribution. Since this distribution ... 1answer 13 views ### Can a piezoelectric material only vibrate at one frequency? Given a material X with piezoelectric properties which is used in a ultrasonic transducer, what determines the working frequency of said transducer? If hypothetically such a transducer is specified ... 0answers 20 views ### How to arrange a 3d cymatics experiment? Various researchers have filmed levitating polystyrene using sound waves. If i were to take 3 speakers and attempt to visualize the standing wave fields formed by the three speakers, how would i do ... 1answer 54 views ### Michelson Morley experiment - why is there an interference pattern in the first place? In descriptions of the experiment, the two arms of the interferometer have the same length. There's an interference pattern which was expected to be shifted when the system was rotated 90 degrees. But ... 2answers 50 views ### The Vectors in v=f\lambda We are learning about waves in physics and I was just wondering what are the vectors and what are the scalars in this function:$$v=f\lambda$$I know the velocity v is a vector so that means that: ... 2answers 51 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 ... 1answer 31 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 ... 2answers 66 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) ... 0answers 11 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 ... 1answer 25 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 ... 1answer 40 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? ... 1answer 35 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 ... 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 ? 1answer 37 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 ... 1answer 44 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? 3answers 52 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 ... 0answers 19 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 ... 2answers 43 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 ... 0answers 48 views ### Did temp change affect the propagation of sound? If yes then how? [closed] propagation of sound is affected by change in temperature. Is it increases or decreases and how? 1answer 24 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 ... 2answers 87 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 ... 3answers 37 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. ... 2answers 80 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 ... 1answer 44 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 ... 1answer 32 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 ... 2answers 62 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). ... 1answer 59 views ### The many faces of electromagnetic waves In my waves and optics class, we have learned several ways to treat electromagnetic waves: light rays (geometric optics), electromagnetic plane waves, spherical waves, cylindrical waves (2D). One ... 1answer 52 views ### Is Huygens's Wave Theory still correct? We have to study on details about Huygens's Wave Theory though we have Electromagnetic theory, quantum theory today. Is it still correct or not? 2answers 48 views ### Please help me with this doubt from spherical waves How to calculate phase difference for spherical waves? How to say whether they are in phase or out of phase? In sinusoidal we can easily say whether they are in phase or out of phase just by looking ... 1answer 27 views ### Is there a material, man made or otherwise, that will 'absorb' visible light and 'reflect' non visible light? using the understanding that energy in any form cannot be indefinitely absorbed, in this case I speak of visible light. Is there a material\substance either man made or natural that will take visible ... 5answers 977 views ### Group and phase velocity - why can the latter be faster than light? [duplicate] The phase velocity can be faster than light. Some argue that the phase velocity doesn't convey information, but this doesn't convince me. We can emit a wave of a single one frequency. Then it will ... 1answer 55 views ### Why do we hear the square of the wave? Assume we superpose two waves of frequencies \omega_1, \omega_2. Then what we get are beats. Adding the two sines gives us$$\psi = A\sin(\omega_1 t) + A\sin(\omega_2 t) = 2 \sin ...
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I was wondering if receivers just catch the radio waves that pass through, or if they actually attract the waves like a magnet. In other words, will a radio wave moving in a straight line bend in ...
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what is phase difference and how to visualize it? i am able to understand it pretty well in sinusoidal waves but please tell me what it is in other type of waves like plane waves,spherical waves,etc.
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### What is the difference in the uses of $\omega t$ and $kx$ in wave equation?

We know that in a wave equation $y = A \sin (\omega t + kx + \phi)$, $y$ = Displacement of particle on y-axis (assuming transverse wave) $A$ = Amplitude $\omega$ = Angular velocity $k$ = wave number ...
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### What are the differences between an EM wave propagating in a conductor and an electrical impulse traveling down a conductor?

I'm afraid I don't quite understand the fundamental and mathematical differences between a propagating electrical signal in a conductor and an EM wave traveling in a conductor. Situation: I found ...
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### Linear polarized 3D glasses and the physical shape of light waves

Looking into how linear polarized 3D glasses work, I keep getting explanations that boil down to this: However, I always assumed that a light wave was depicted in diagrams like this... ...to more ...
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### Intuition behind Airy waves dispersion relation

Using Airy wave theory, one can derive the dispersion relation of water waves (under some physical assumptions): $$\omega^2 = gk\tanh{kh}$$ where $k$ is the wave number, $h$ the distance from the ...
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### Why is TV remote's infrared wave shown by a camera as purple light, why not red or something else?

I've always seen that all the old model remotes that is used in DVD players or TVs, it emits electromagnetic waves, having wavelenth somewhere in the Infrared region. But when my phone's average ...
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### WHY do waves diffract - what is the mechanism behind the diffraction?

Having recently studied wave diffraction at an introductory level, I don't feel that I understand why waves diffract like they do. What is it about the obstacle or the waves interaction with it which ...
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### Can sound reflect from itself?

If it is possible, what kind of conditions would be necessary? The case with electromagnetic waves could also be interesting, but I don't think that is possible.
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### How do transverse sound waves (in solids) convert to longitudinal waves (in gases)?

I know that in solids sound can be a transverse wave and that in gases it is a longitudinal wave. The question is what happens at the boundry at the two substances? What is the mechanism of conversion ...