Wave Definition and 999 Threads

I have a concern about having some wave function psi, that is originally a superposition of many eigenstates (energies). Traditionally, it is said that the square of the coefficient of each of the component eigenfunctions represents the probability of measuring this particular energy eigenstate...

This article is about using P wave symmetry for super conductors, can you explain what a P wave is and why it is needed for super conduction please https://www.sciencedaily.com/releases/2017/01/170119084619.htm

Hi everyone, I'm having some difficulty comprehending "normal" transmission of stress/strain through a solid body and "shock" transmission of stress/strain. Imagine I have two bodies, one rigid - the other elastic. If the rigid body is fixed in space, and the elastic body is flying at the...

For the wave traveling towards left, the equations is Asin(kx + ωt). How does the same mathematical equation explain the possibility of two initial conditions. In the case of the wave traveling towards right, Asin(kx - ωt) and Asin(ωt - kx) gives two initial conditions Asin(kx) and - Asin(kx) on...

Homework Statement "assume that the three real functions ψ1,ψ2, and ψ3 are normalized and orthogonal. Normalize the following function" ψ1 - ψ21/(sqrt2) + ψ3sqrt(3)/sqrt(6)Homework Equations This is for a physical chemistry class. I haven't seen an example like this. All that is in our...

I would really like some confirmation / clarification on the following points that I am trying to understand in terms of modern physics. I would really appreciate if anyone might correct and complete my misunderstandings: 1 One can consider light as a wave. 2 As a particle, a photon may be...

Homework Statement The time for which the diode conducts is Homework Equations Using integration and differentiation Vc = 1 / C integral (current)(dt) The Attempt at a Solution Vs = -Vc Vm sin(wt) = -Vc = - (1/C) integral (Idt) now differentiate both sides to get expression for I that is...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] Slightly confused here. Since this is a displacement-time graph, is it correct to say that at X, since the displacement is zero that it can't be a point of compression because that would imply the air molecules are moving...

Homework Statement phi(x,t) = A e *[-a(bx+ct)*2] I'm trying to find the speed of the equation Homework Equations f(x+vt) +vt which means it is in the negative x-direction f(x)= e^-ax^2 plugging in x'=x+vt A e *[-a(bx+ct)*2] where a= constant A= amplitude...

Hello, Sound waves are always introduced as longitudinal mechanical waves: the medium particles oscillate in a direction parallel to the direction of motion of the sound wave. We can only hear sound frequencies between 20Hz and 20KHz. For us to hear these mechanical sound waves, the waves need...

Is it correct to state that a progressive wave, originates when a simple harmonic motion is imparted continuously to adjacent particles from one direction to another moving with a velocity v. Using this idea, substituting (t - x/v) instead of t is the simple harmonic motion function...

I have been thinking about this. For a wave equation, the acceleration of a point on a drumhead is proportional to the height of its neighbors $$U_{tt}=\alpha^2\nabla^2U$$ The heat equation, change in concentration or temperature is equal to the average of its neighbors...

Hi, I want to ask about the Wave behavior of light. Fine, I know all about the slit experiments and the resultant interference patterns - but I want to ask about the physical context. So light is the carrier of electromagnetic force, and thus its wave oscillation pattern represents an...

Homework Statement 3 tuning forks of frequencies 200, 203, 207 Hz are sounded together.find out the beat frequency. Homework Equations Beat frequency= n1-n2 (n=frequency). The Attempt at a Solution I know that beat frequency is the difference in the frequencies of two superposing notes. But...

What are the factors that determine the property of wave penetration of bodies? For instance we can listen to fm radio from inside the walls of a room. But visible light is unable to penetrate the walls. Similarly some metals reflect some frequency but absorb some. How atomic orbitals play...

Text books often give an expression like Asin(kx-ωt) as a solution of the wave equation, but they don’t show how to arrive at this solution. Other textbooks, which go through the complete solution process of the wave equation, determine the coefficients using Fourier series. My goal was to get...

Is there a relationship between the quantization of an object and its wave function? If an object isn't quantized does it have a wave function? For example, in string theory branes are not quantized, so do they have wave functions?

Do higher dimensional branes, like the super membrane (which is a 2D brane) or the NS5/M5 brane, have wave functions? I know that they become unstable once they are quantized, but does that mean that they do not have wave functions? You will never here about any thing regarding an M2 wave...

does ever sound wave have a positive and negative frequency?

Suppose the Copenhagen interpretation is correct. And we reverse time, what happens. If a wave function has collapsed, and we found a particle somewhere. Now, I turn back time( just hypothetically), what would happen? Would the wave function uncollapse and would the particle then appear at some...

Hellow i want to ask about guessing the trial wave function at variational method of approximation usually for example at solving harmonic oscillator or hydrogen atom we have conditions for trial wave function but in fact i want to ask generally how could i make the guessing .. some problems...

Homework Statement Flat harmonic electromagnetic wave propagates in the positive direction in vacuo axis y. Vector electromagnetic energy flux density is given by: S(y,t)=Sm *cos(wt-ky)2.Wave value: k=(2*π)/λ=0.41 m-1,Amplitude Sm=26 W/m2.Compare this wave with another wave. Homework Equations...

I don't understand the difference between the Jeans Mass and the fundamental mode. Both are reaching till the horizon but according to me is the Jeans mass not oscillating. So what is the relation between a Jeans mass and the fundamental mode of the acoustic waves?

I selected the Name "Rogue Wave" because I do a lot of boating. Rogue Waves have recently been accepted into the scientific community as a fact of nature. For centuries sailors and captains have spoken of them but, was considered to be "Tales of the Oceans". Science does move at a very slow rate...

Schrodinger developed his famous wave equation which describes how the quantum state of a system changes over time. But, what was Schrodinger trying to initially prove with his equation?I assume that it has to do with Debrogile's hypothesis. I know from my classes that we use the Schrodinger...

Homework Statement The longitudinal displacement of a mass element in a medium as a sound wave passes through it is given by s = sm cos (kx – ωt). Consider a sound wave of frequency 330 Hz and wavelength 0.95 m. If sm= 16 µm, what is the displacement of an element of air located at x = 1.1 m...

Is it possible to build the full wave function for a simple problem in QM, such as an infinite well, without any experimental data ? I'm learning about QM, and I saw how to compute energy states (the wave function for each allowed energy level) in some usual QM basic problems. But then, I was...

Homework Statement Many sources of electromagnetic waves (stars and light bulbs, for example) radiate in all directions. A simple example of the electric field for a monochromatic electromagnetic wave produced by a spherical source is $$E(r,\theta,\phi,t)=A\frac{\sin \theta}{r} \big(\cos...

Why RMS values change during half wave rectification, full wave rectification? And why does RMS value remain constant during smoothing?

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > A transverse wave on a string has an amplitude of 16cm, a wavenumber of 5.7m-1, and a frequency of 39Hz. What is the propagation speed of that wave? (a) 6.84 m/s (b) 39.2 m/s (c) 43 m/s (d) 6.24...

Homework Statement http://i.imgur.com/sWZS9vQ.png Homework Equations P=½ √μF ω2 A2 The Attempt at a Solution How is the equation related to the wavelength? Thanks

For example, I am following the below proof: Although the above derivation involves a projection on the position basis, it appears one can generalize this result by using any complete basis. So despite it not being explicitly mentioned here, are all wave functions with any continuum basis...

From the path integral approach, we know that ## \displaystyle \langle x,t|x_i,0\rangle \propto \int_{\xi(0)=x_i}^{\xi(t_f)=x} D\xi(t) \ e^{iS[\xi]}##. Now, using ## |x,t\rangle=e^{-iHt}|x,0\rangle ##, ## |y\rangle\equiv |y,0\rangle ## and ## \sum_b |\phi_b\rangle\langle \phi_b|=1 ## where ## \{...

I need to solve Cn for a wave function, and have reached the following integral: Cn = -[√(1/a)](a/nπ)[cos(nπx/a)(ψ1(x)+ψ2(x))+∫cos(u)(dψ1(x)/dx)dx+∫cos(u)(dψ2(x)/dx)dx]This is a simplified version of the original equation, for elaboration Cn is the constant for linear combinations of a wave...

Homework Statement Alas, after a sybaritic festival, the cheap upright piano in your fraternity house is found upright at the bottom of the house swimming pool. You decide to play Handel's Water music but first test the sound of middle C (261.6 HZ). The speed of sound in water is...

Homework Statement Homework EquationsThe Attempt at a Solution So I was given the electromagnetic E field equation in phasor form and I converted it to sinusoidal form. Is it correct ? Also will it be a reflected wave since we have (wt+Bz) and not (wt-Bz) ? Also will it be circularly...

Homework Statement A sound wave with intensity 2x10^(-3) W/m^2 is perceived to be modestly loud. Your eardrum is 6.0 mm in diameter. How much energy will be transferred to your eardrum while listening to this sound for 1.0 min? Homework Equations P=IA=(intensity)(area) =2x10^(-3) * (pi...

Hi. I'm a bit puzzled that the classical formula for the intensity of a monochromatic, linear EM wave $$I=\frac{1}{2}\cdot c\cdot \varepsilon_0\cdot E_0 ^2$$ seems to be independent of frequency whereas I find for the energy of a mechanical wave (e.g. on a string with total mass ##M##)...

Homework Statement Simple question we have to answer: (Physics) How do I release the electrons from the cathode with a color filter? (The so called Photoelectric effect)Homework Equations none The Attempt at a Solution[/B] Here we have a conflict , the so called wave-particle duality, if...

How do you find the wave function Φα when given the Hamiltonian, and the equation: aΦα(x) = αΦα(x) Where I know the operator a = 1/21/2((x/(ħ/mω)1/2) + i(p/(mħω)1/2)) And the Hamiltonian, (p2/2m) + (mω2x2)/2 And α is a complex parameter. I obviously don't want someone to do this question...

Homework Statement The tension in the string is 90N; the string is 60cm long and has a weight of 34.44g. What is the speed of the wave on the string? Answer: 396 m/s Homework Equations v = √ T / (m/L) The Attempt at a Solution v = √ 90N / (0.0344kg/0.6m) v = 39.6 m/s Huh? This looks like it...

Homework Statement Assume a wave packet is has contributions from various frequencies, give by g(ω)=C for |ω|<ω0, and g(ω) =0 for elsewhere. a)What is the signal strength as a function of time, i.e., V(t)=? b) Sketch g(ω) and V(t); You can use fooplots.com, for example, or python. c)...

Homework Statement An interaction occurs so that an instantaneous force acts on a particle imparting a momentum ## p_{0} = \hbar k_{0}## to the ground state SHO wave function. Find the probability that the system is still in its ground state. Homework Equations ##\psi _{0} =\left(...

I have been trying to understand why two woodwind bore shapes behave so differently. My understanding is that one end of a woodwind is an antinode (driven by the reed of the instrument) and the other end is a node (where the tube is open to the atmosphere). a - - - - - - - - - - n In the...

Homework Statement A long rope with mass m = 10 kg is suspended from the ceiling and hangs vertically. A wave pulse is produced at the lower end of the rope and the pulse travels up the rope. (a) Explain why the speed of the wave pulse change as it moves up the rope; does it increase or...

As the universe expands and is per definition gravitationally decoupled on long distances and the overall metric therefore is "flat" and apparently no gravitational background exists, the question in some discussion arose: Can GWs propagate in in a gravitational empty space at all? If not, and...

It is hard not to hear that NASA has just published paper claiming confirmation of "impossible drive" - closed resonant chamber: http://arc.aiaa.org/doi/full/10.2514/1.B36120 http://www.sciencealert.com/it-s-official-nasa-s-peer-reviewed-em-drive-paper-has-finally-been-published...

Hi, I wonder why we assume the matter wave of an electron is standing wave. Is there any reason why it has to be standing wave?Is it because standing wave is the right "wave equation solution" that satisfies integer multiple behaviour of bohr model?

Homework Statement I don't see how the author normalizes ##u(r)=Asin(kr)##. From Griffiths, Introduction to Quantum Mechanics, 2nd edition, page 141-142: http://imgur.com/a/bo8v6 Homework Equations ##\int_0^{\infty} \int_0^{\pi} \int_0^{2\pi}|A|^2 \sin^2(\frac{n\pi r}{a})r^2 \sin \theta...

Imagine that you have plucked a string and it is vibrating as a standing wave at its fundamental tone (frequency f1). You leave it there and later on come back with the intention of bringing it up to the second tone (frequency f2). What should you do? It seems obvious: apply a stimulous...