Waves are disturbances that propagate throush 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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Do photons occupy space?

Total noob here. I realize that photons do not have a mass. However, they must somehow occupy space, as I've read that light waves can collide with one another. Do photons occupy space? and if so, ...
0
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0answers
41 views

Drawing the wave function for a wave packet

I have the following infotmation: Amplitude-Function: $U(k) = Ae^{-a|k-k_0|}$ Wave Function: $u(x,t) = \frac{A}{\sqrt{2\pi}} \frac{2a}{(x-vt)^2+a^2}e^{ik_0(x-vt)}$ Uncertainty in x: $\Delta x = 1$ ...
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2answers
90 views

What is the lenght of the rope?

The $E$ string of a violin has a linear density of $0.5 g / m$ and is subjected to a $80\text{N}$ of tension, tuned for a frequency $u = 660 \text{Hz}$: What is the length of the rope? I know ...
3
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3answers
112 views

Why do tunneling photons outrace their non tunneling counterparts in vacuum?

If we describe a photons with a wave packet, moving towards a potential barrier and E smaller than V, there is a finite chance that it will tunnel to the other side. In this process it is likely that ...
0
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1answer
68 views

What can cause a change in wave's shape - One dimensional wave

what can cause a change in wave's shape of one dimensional wave moving through a rope? It's velocity ? or the wave's length ? What can cause him change his shape.
0
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1answer
68 views

Spring Constant - Waves

I tried to prove that for the same length of spring , a one dimensional wave that moves faster in spring 2 than spring 1, its spring constant will be lower than the spring constant of spring 1. ...
0
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2answers
73 views

Need help visualising transverse waves

From studying waves I find that I can visualise longitudinal waves where the wave propagates in the direction of the displacement. However I don't understand what causes the propagation perpendicular ...
1
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1answer
44 views

Can the motion of a cracking whip be described as the interference of two waves?

I was watching a whip crack in slow motion and I noticed that the motion of the whip could be described using two different circular descriptions. 1) the user circles the whip around over his head, ...
2
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1answer
36 views

Understanding the displacement of a particle in a wave

I have a question regarding waves and the equation we use to describe their motion. My understanding feels shaky, so i'd like to see if I can get a good explanation/way of thinking about it. The ...
1
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1answer
51 views

Does sound gets faster when air bubble is supend in water?

Does sound gets faster when air bubble is suspend in water? c = sqrt(K/P) c = speed K = bulk module P = density When air bubbles is homogenized into water the density is lower, so should sound ...
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0answers
43 views

How do I get around the fact that boundary conditions don't apply in the equation's region of validity?

A tight string lies along the positive x-axis when unperturbed. Its displacement from the x-axis is denoted by $y(x, t)$. It is attached to a boundary at $x = 0$. The condition at the boundary is ...
3
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3answers
215 views

Can a wave possess spin?

Since a matter wave is associated with a particle in quantum mechanics, does the wave spins? I mean, can we visualize the spinning of wave or is it possible that the wave spins?
0
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1answer
53 views

Why the crest of water absorb more light than the trough of water?

I have done my experiment using water ripple to study the behavior of waves. I know that the crest will absorb more light than the trough so that the image created on the white paper sheet appeared to ...
1
vote
1answer
142 views

Why maximum energy transfer at natural frequency even if max amplitude occurs below $f_0$

This is a paragraph from my book: "For a damped system, the resonant frequency at which the amplitude is a maximum is lower than the natural frequency.However, maximum transfer of energy, or energy ...
2
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1answer
76 views

Tuned Mass Damper

I was learning about the different applications of resonance and one of them is the tuned mass damper used in buildings. One thing I am confused about is as to why the mass attached to the building ...
1
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1answer
46 views

Properties of 3D waves [closed]

I have a few questions about 3D waves: Are all 3D waves types of electromagnetic radiation? Are all 2D waves mechanical?
2
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2answers
53 views

Can a force applied to a wheel find the fastest way of getting to the other side?

I haven't studied much about this, so if I am mistaken about something please correct me. From what I have seen around the Internet, a force applied to a object takes time to propagate through the ...
3
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0answers
227 views

“Derivation” of the Heisenberg Uncertainty Principle

Ok, so I posted this in the mathematics StackExchange, but got no response. The question I outline below is my textbook's "derivation" of the Heisenberg Uncertainty Principle. The "derivation" my ...
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2answers
66 views

Is there just one fundamental frequency?

I read simple definitions of the terms frequency, and fundamental frequency, which defined them thus, Frequency: the number of occurrences of a periodic wave during a second Fundamental Frequency: ...
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1answer
47 views

Reason for the experiment [closed]

Why is the independent confirmation by separate experiments such as important part of the development of the idea of the existence of electron wave?
2
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1answer
96 views

Does timbre consist in pitch and volume?

I read that the physical properties of a sound wave correspond to its audible qualities: pitch, volume, and timbre. However, an oscilloscope uses only two-dimensions to accurately depict the physical ...
5
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2answers
376 views

Which solution to the electromagnetic wave equation is the most accurate model of monochromatic light?

When a photon is modeled as a monochromatic electromagnetic wave its electric and magnetic components are usually taken to be sine waves (for example here ...
3
votes
3answers
156 views

Calculating the mass of a wave of water

I am assuming it is possible to calculate the mass of water if the volume is known. My assumption is that doing this for stagnant water, in a container perhaps, is easy. However I want calculate, ...
2
votes
1answer
58 views

Is polarization of a wave just a description of its motion in three dimensions?

Since a polarization of the wave is described by complex numbers, we can try to give that mathematical formalism geometrical meaning. With having two different axes, one imaginary and other real, it ...
1
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1answer
206 views

Why does diffraction depend on wavelength? [closed]

We've all heard of the diffraction of radio waves over a mountain and the diffraction of water waves through a gap, but why does this effect depend on wavelength? I'm looking for as simple answer as ...
1
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1answer
59 views

Modeling Water Surface Impact

I have a project that is to model the wave equation in a pond due to a pebble being thrown in. The project is quite simple as all we really have to model is the wave equation with an initial ...
0
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0answers
23 views

What's the proof that the polarization occur s to the electric field of the light? [duplicate]

What's the proof of the light polarization that it happens to the electric field and not the magnetic field? How did Malus discover that the light is polarized although he didn't see the waves ...
3
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2answers
274 views

Why doesn't the magnetic field polarize when polarizing light?

If the magnetic field doesn't polarize does it follow the electric field path of propagation? or does it vanish?
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0answers
37 views

Stationary wave on a string

The problem says: A string lies on the x-axis, and is fixed at $ x=-a $ and $ x=a $. At $ t=0 $ we impose a transversal velocity given by $ a^2-x^2 $. Assuming that the velocity of the wave is $ c ...
4
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2answers
104 views

Do mechanical waves travel in straight lines?

Electromagnetic waves travel in straight lines but do all waves travel in straight lines?
2
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3answers
484 views

How to “derive” the wave equation without refering to strings?

The wave equation in $3$ dimensions is simply: $$\nabla^2\psi = \dfrac{1}{v^2} \dfrac{\partial^2}{\partial t^2}\psi,$$ and the intuition behind this is that at each point of space with coordinates ...
2
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3answers
147 views

Does interference take place only in waves parallel to each other?

The title says it all but I will add some details. I believe that interference takes place only in waves which are parallel to each other. See the picture to understand what I mean by parallel. We ...
4
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2answers
131 views

Why are two voices singing the same note louder than one?

Let's say for example: Two people sing the same note (frequency) and volume (amplitude) together. Why is it that the two persons sound louder than they would ...
3
votes
2answers
43 views

Why a minus in the equation of a paraxial plane wave?

paraxial plane wave = $\exp{(-jkz)}$ for waves propagating to the right I can't figure out why it's not $\exp{(+jkz)}$. Any help would be greatly appreciated, thank you.
3
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2answers
89 views

Locations of destructive interference for two spherical waves

I have looked at this, but it did not help with locations. Really this just comes down to mathematical manipulation, which for some reason I fail to see. Here is my paraphrased setup: Consider two ...
1
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0answers
69 views

Number of wave modes in a cavity

I'm trying to calculate the number of acoustic modes that can exist in a room in a certain range of frequencies. I thought of using the Rayleigh-Jeans formula for the electromagnetic standing wave ...
3
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3answers
104 views

When polarized light hits a polarizer, what happens to the polarization which is not transmitted?

It is typically said that in polarization of light only those waves can pass through a polaroid which has a plane of vibration parallel to the axis of polaroid. My question is: what happens to the ...
7
votes
1answer
229 views

Are small speakers inherently limited to higher frequencies?

I am hoping to build a subwoofer using multiple smaller speakers (165mm) instead of a single larger speaker (380mm). My theory is that the displaced air volume is what matters, not the individual ...
1
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1answer
189 views

How to calculate loss due to Gaussian beam divergence of a laser going through multiple lenses?

To better explain my question, I will need to give a brief description of the configuration used in 2D MEMS switches. So, the next figure shows a configuration of a 2D MEMS switch, a light beam ...
22
votes
4answers
574 views

Is the existence of electromagnetic standing waves dependent on the observers reference frame?

If I take two plane EM waves travelling in opposite direction e.g. $E = E_0 \sin(kx-\omega t)$ and $E=E_0 \sin (kx + \omega t)$, they sum to give a standing wave with a time-averaged Poynting vector ...
1
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0answers
59 views

Can anyone outline the theory of plane wave Born approximation for direct nuclear reactions in detail?

Can anyone outline the theory of plane wave Born approximation for direct nuclear reactions in detail? Also What are the modification introduced in the distorted wave Born approximation? I was ...
12
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2answers
712 views

First-order wave equation: Why is its presence not common?

The (one-dimensional) wave equation is the second-order linear partial differential equation $$\frac{\partial^2 f}{\partial x^2}=\frac{1}{v^2}\frac{\partial^2 f}{\partial t^2}\tag{second order PDE}$$ ...
0
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2answers
265 views

How do the particles in a standing wave vibrate in phase within half a wavelength?

I would like to have a better understanding of phase difference when talking about stationary waves. How exactly are particles in phase within half a wavelength in a stationary wave?
3
votes
1answer
100 views

Why is the water on one side of a bridge choppy?

My daily commute take me across the Evergreen Point Floating Bridge on Lake Washington. I have noticed on several occasions that the water on the southern side of the bridge will be quite choppy ...
1
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3answers
281 views

How could electromagnetic waves propagate through space although they have no electrons?

How could electric fields in these waves propagate through space although in space there's no electrons for the electric field to be formed? is there another type of charged particles that carry the ...
0
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0answers
49 views

Why in 2+1 spacetime dimensions electromagnetic wave (light) cannot be distinguished with acoustic wave (mechanical wave)?

I have heard a saying that in 2+1 spacetime dimensions electromagnetic wave cannot be distinguished with acoustic wave. Or maybe they want to say in 2+1 spacetime dimensions photon and phonon cannot ...
3
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1answer
273 views

Why do we must initially assume that the wavefunction is complex?

The sound waves are real, and they can interfere, so corresponding apparat may be used in quantum mechanics. We also may use the time dependence in a form of orthogonal matrix multiplying the initial ...
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1answer
52 views

What are the the characteristics of a standing wave? [closed]

May someone explain #24 from this picture? B is apparently the correct answer. Can any of the other answers be correct here? Isn't D also correct?
1
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1answer
95 views

Does the transmission axis matter for sending polarized light through polarized glass?

If I have polarized light and I send through only one polarized glass plane, does the transmission axis matter, or will the intensity be halved no matter what.
0
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2answers
317 views

Deriving group velocity formula

A formula for the group velocity of waves is: $u=k*dv/dk + v$ But then, since $k=2π/λ$, this equation can be rewritten as: $u=v-dv/dλ*λ$ But how? My attempt: $k*dv/dk$ = $((2π/λ)*dv/d(2π/λ)$ ...