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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Are there any ways to alter frequency of wave?

I want to know how can we change frequency of wave, both sound and light, and what is the nature of "changing frequency" Such as, any material could absorb and re-emit wave in another wavelength. Or ...
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19 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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19 views

Distribution of refractive index of water when applied pressure wave

I was wondering when applying pressure wave, ultrasonic sound waves, under water, how I would be able to measure the distribution of the refractive index.
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23 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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1answer
86 views

Thin-wedge Interference Problems (Classical Waves Problem)

I would like to solve the problem on the following image: My question is: Why is the answer to (a) a minimum? When the light wave hits the top surface of the top glass, a wave will be reflected ...
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67 views

about superposition of two sinusoidal waves

I am reading a material on introduction of interference and superposition. To go deeper, I want to know how the math works in superposition, from wiki ...
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32 views

Modeling the creation of transverse waves

Suppose I hang one end of a jump rope against a wall and start waving the other end. I'm interested in knowing the behavior of the jump rope as it starts generating waves. In other words, how can I ...
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1answer
21 views

Intensity of Sound Wave

Is the intensity of a sound wave same at all the points through which the wave travels? The formula for intensity is $ I = \frac{{p_0}^2 }{2 \rho v}$. But this does not make sense to me. Shouldn't the ...
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225 views

Does a wave experiencing a total internal reflection penetrate the medium in any way?

Let me explain my concern usingn this picture: At the point of total internal reflection does a fraction of the wave get into medium 2? I would imagine it should happen because of the uncertainty ...
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31 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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89 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 ...
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33 views

Appropriate order of the sources in the phase difference formula (Waves)

Please look at b). My teacher defines delta(x) to be x1-x2 and then says that phi naught of 1 =0. However, because she defined the difference to be "1"-"2", the phi naught difference should also be ...
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3answers
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Double-Slit Experiment Separation Between Fringes

I was taught in class that the double slit diffraction pattern would always have bright fringes of same length. We derived the formula: $y=m(\lambda)(L)/d$, which also shows this equal distance. I ...
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63 views

Why is a particular wavelength favored by transmission through a thin film?

A sheet of glass is coated with a $500\text{ nm}$ thick layer of oil ($n=1.42$). For what visible wavelengths of light do the reflected waves interfere a) constructively? b) destructively? ...
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36 views

Propagation of sound waves and monopole

While it is understood that in order for the acoustic waves to reach far field the wavelength should be less than the characteristic length of the source, I am not able to physically understand how? ...
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46 views

Radar Vs. Sonar

What is the true difference between radar and sonar? My understanding is that radar uses a reflected EM wave, while sonar uses a compression (shock wave) of the material it's in. (It compresses water, ...
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83 views

Why can we leave off half of the general solution?

In these pdf notes, it says at the bottom of the first page and beginning of the second: [...] whose solution is: $$\Psi(\theta) = c_1 e^{i\omega\theta} + c_2 e^{-i\omega\theta}$$ Since we are ...
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46 views

Is there a specific branch of physics that studies waves?

Is there a branch of physics that studies waves and how they propagate through air, wires etc.?
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76 views

Spherical wave amplitude near to source

Let us assume, I generate spherical waves from a point source, of the form $f(t)=\sin(t)$. At $r$ distance, it will be $\sin(t)/r$. Let us take $r = 0.1$ for example. Then, at this distance, the ...
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41 views

What is the physical explanation for the phase relationship between acoustic pressure and particle velocity in plane and spherical waves?

I've been looking around for a decent physical explanation of the differences in the phase relationships between acoustic pressure and particle velocity in different types of waves. Mathematical ...
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24 views

What the phase constant difference required for sources located at the same location?

Here is what my teacher wrote on her notes: Let's say there are two speakers located at x=0m emitting sound waves of same $\omega$ and same A. PHASE CONSTANT DIFFERENCES If A < A'<2A: there is ...
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1answer
54 views

General equation of a wave

My book says that functions which represent a wave motions satisfy the differential equation : $$ \frac{\partial^2 y} {\partial^2t} = v^2 \frac{\partial^2 y} {\partial^2x} $$ where $v$ is the ...
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55 views

Modulus of rigidity inside the water

Transverse wave can't travel inside the water. It travels in solid and on the surface of water because they have modulus of rigidity. What is modulus of rigidity? and why there is no modulus of ...
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What is the mathematical equation for a sine wave? [closed]

(Guitar player and programmer here, don't know much about math. So go easy ;) ). I recently learned that an audio sine wave is called that way because it is of the shape of the graph of a sine ...
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85 views

Equation of motion for system of springs

I need to find the equations of motion for the following system. If $x_1$ is $m_1$'s extension and $x_2$ is $m_2$'s, then, I feel like for $m_1$ we just need to consider $x_1$ giving $$m_1 a_1 = ...
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18 views

Sound Source Power Formula Approximation

A sound source emits waves with a wavelength of 25 cm. 50 m away, the waves have an amplitude of 4 micrometers. It's 20 ° C outside and the density of air is 1.3 kg/m^3. What is the power of the ...
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72 views

What are overtones and how do they relate to harmonics?

Problem 43. Two organ pipes, a pipe of fundamental frequency 440 Hz, closed at one end, and a pipe of fundamental frequency 660 Hz, open at both ends, produce overtones. Which choice below ...
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Oscillation of air particles and speed of sound wave

A sound wave is essentially air particles oscillating parallel to the direction of travel of the wave. We learnt that $v = f\lambda$, where $v$ is the speed of the wave, $f$ is the frequency of the ...
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69 views

Why are speakers louder in a corner?

You can test this very easily using an iPhone's speaker pointed towards a wall. When the speaker is more than an inch or two away, it is normal volume. However, when the speaker is nearly touching the ...
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1answer
27 views

Finding the distance between two osclilating particles in a wave

Assume a wave function $\psi = \psi(x,t)$ where $x$ is position from the starting point $(0,0)$ and $t$ is time. Two oscillating points A and B are located at $x_1$ and $x_2$ respectively with $x_2 ...
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1answer
58 views

How does underwater sound sound?

I have been thinking about underwater sounds (i.e. sounds produced and recorded underwater), what exactly the water does, and how to emulate this effect. Imagine a sound played underwater (e.g. from ...
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47 views

Proving standing waves equation for open-open pattern [closed]

My teacher assigned me to prove open-closed and closed-closed standing waves patterns using math. With closed-closed, it was fairly easy: $$\begin{align} D(x=0,t)&=0\\ D(x=L,t)&=0=2A\sin(kx) ...
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74 views

Do waves accelerate?

Typically we think of acceleration as a particulate property but a previous question on this forum got me thinking. If we think of a wave increasing its velocity by increasing its energy/frequency ...
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22 views

Sound system and Temperature Effects

You arrange a patio with a sound system. Ignore all sound reflections. If you are at a certain location on the patio, you can find the two lowest frequencies you will experience total destructive ...
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32 views

Speakers and Changes in Temperature

Let's say that there is a speaker that oscillates the same way. Now, let's say there is a sudden drop in temperature. I know the speed of sound would drop. But, what will drop, the wavelength or the ...
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27 views

Sound waves travelling in air and the amount of air affected by the wave

If there is a sound wave travelling in the air, will the amount of air transported by the wave be proportional to the intensity? Here is my answer: yes, because as the energy of the wave is related ...
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1answer
59 views

Can we measure the depth of water by scattering water?

Suppose we release an object and make it fall on the surface of water, then the scatter of water is recorded, Taking some observations, can we calculate the depth of the water by analyzing the ...
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1answer
38 views

Conditions for characterizing a wave as plane wave

Given a wave equation, say for example $\Psi(x,y,z,t) = a \cos\left(\omega t -\vec{k}\cdot \vec{r} \right)$, what conditions should be met for $\Psi$ to represent a plane wave?
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1answer
30 views

Doppler effect and acceleration's impact

Can anyone explain why they say Doppler effect does not depend on acceleration? Would having acceleration not affect the frequency? If the source emits the first circular wave, moving at 50 m/s ...
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64 views

Definition of transmission and reflection probability

This is a basic question, but it does not seem to be well defined anywhere. Generally, two terms are mixed somewhat randomly: transmission PROBABILITY and transmission coefficient. So to be clear, ...
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209 views

Physical meaning of imaginary part of Electric field?

As far as I know (or I thought I knew), if we have an electric field $$\mathbf{E}=\mathbf{E_0}\cos(\omega t - kx),$$ we can define it as the real part of $$\mathbf{E}=Re(\mathbf{E_0}e^{i(\omega t - ...
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224 views

Why do 2.4GHz frequencies offer greater range than 5GHz routers?

I would've thought that as 5GHz is a higher frequency, and it carries more energy, it would be able to pass through walls much more easily compared to a 2.4GHz frequency- similar to how short ...
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1answer
75 views

Is the photon first a wave, then a particle? [duplicate]

When the 'photon' is emitted, it would reason that the result of the energy fluctuation that creates 'it' rather is created as an energy wave, which when measured by us or a surface, it 'becomes' as a ...
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66 views

Coherent sources for interference

Regular interference pattern can be observed if the two wave sources are coherent. Two sources are coherent if they have the same frequency and constant phase difference. Could someone please ...
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1answer
43 views

Determining the decay constant for a damped wave [closed]

My question is short and simple. If a damped, travelling wave (say on a string) could be described as $y\left( x,t\right) =Ae^{-\gamma x}\sin \left( kx-\omega t\right)$ how could/would one ...
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0answers
52 views

Wave Packets, Group velocity, and Phase velocity [duplicate]

Mathematically, you find that the wave function of a particle $\Psi (x,t)$ moves with the same velocity as the velocity of the particle ($v_{particle} = v_{group}$). Is there a reason why the ...
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3answers
372 views

Does the speed at which sound travel depend on the volume (amplitude) of the sound?

Lets say you have a plank is you hit it once and get t time if you hit is 2x as hard will it travel t/2? will it be the same or will it travel only slightly faster?
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Why does a wave actually diffract?

I know that waves diffract around a slit and this is due to the Huygens-Fresnel principle. But I never understand this in an intuitive wave that why does a wave become a spherical wave front at the ...
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0answers
46 views

Calculate signal strength received by an Ultrasonic Transducer [closed]

Below is an image showing transducer A transmitting a signal with an amplitude of 3000mV, I am trying to calculate the amplitude of the signal received by transducer B in mV, I understand that there ...
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Convention about delta x in Waves Interference

They seem to adopt a convention that delta x must always be positive. Otherwise, there is no way to know what the phase difference of the sources actually means. Does a 90° difference mean that ...