Wave Definition and 999 Threads

We want to solve the equation. $$H\Psi = i\hbar\frac{\partial \Psi}{\partial t} $$ (1) If we solve the following equation for G $$(H-i\hbar\frac{\partial }{\partial t})G(t,t_{0}) \Psi(t_{0}) = -i\hbar\delta(t-t_{0})$$ (2) The final solution for our wave function is, $$\Psi(t) =...

Hi. We tried to make some quantitative measurements with a Pasco ripple tank system, a video camera and software for video analysis. We generated circular waves and tracked the propagation of a crest, from which the software computed the phase velocity: We used 5 Hz, 10 Hz and 20 Hz...

Homework Statement The problem is shown on the photo. And the actual answer is A. 0.5s, and I thought it would be B. 1.0s Homework EquationsThe Attempt at a Solution Here is my thought, The journey from A to B is just a half period, then the whole period would be 4s, as a result, the time it...

We know that skin depth in a conductor is found using the following expression, (Credits: http://farside.ph.utexas.edu/teaching/315/Waves/node65.html) Basically, as the wave propagates in a conductor, it's electric field strength reduces and reaches 1/e of it's initial value at the skin depth...

Hi, there is no particular question that I need help on, just something my lecturer told us in lesson which I couldn't quite understand so i'd like to check my understanding on this. I know that the speed of a soundwave is 'c' in undisturbed flow. Suppose the flow velocity is 'U'. If the...

Does a single photon travel in two different waves at once? If photons are particles like the Photoelectric Effect, Compton Scattering, and Blackbody radiation all suggest, how do polarizing filters block light completely? Is a particle from a radio antenna actually that large in size?

I am interested in the derivation of Schrödinger’s wave equation from the Klein Gordon equation. I have looked in Penfold’s ‘The Road to Reality’, the open University’s Quantum Mechanics books, Feynman’s lectures, the internet, but not found what I want. Everyone seems to take it as a given...

In classical electrodynamics energy of a wave is proportional to its intensity , this theory fails when Hertz did experiment on photoelectric effect. Is my statement is correct? If not correct me.

For this problem at t=0 Ψ(x,0)=Ψ1-Ψ3 Where Ψ1 and Ψ3are the normalised eigenstates corresponding to energy level 1 and 3 of the infinite square well potential. Now for it's time evolution it will be Ψ1exp(-iE1t/ħ)- Ψ3exp(-iE3t/ħ) And taking the time given in the question the time part of the...

Homework Statement Homework Equations For this question my ans. is coming option (3) since the time part of the wave comes out to be same for both the energy states which is (-1)^(-1/8) and (-1)^(-9/8) respectively (using exp(-iEt/ħ)). But the correct option is given option (4). Am I right...

Homework Statement [Answer is V = 25m/s, however, how do I get that answer? Thank you!] A police cruiser sets up a novel radar speed trap, consisting of two transmitting antennas at the edge of a main north-south road. One antenna is 2.0 m [W] of the other. The antennas, essentially point...

For a wave A sin ( kx - ωt) and a wave A sin ( kx + ωt) traveling opposite to each other, on evaluating by applying superposition principle , the resultant displacement function is 2A sin ( kx ) cos (ωt) . For different Node Anti-node configurations we calculate natural frequencies of the...

Homework Statement There's a bucket, filled about halfway with water. The water itself is completely still. A perfect sphere with mass m and volume v are given. The depth of the water, and the radius of the bucket (which may be considered perfectly cylindrical) are both given. In short, you...

I want a clear formula for clear water (and salty water) penetration by giving only the radio wave frequency . I searched the web , the formulas on the web are so complicated . Are there any simple formula available for that ?

When there is electric charge, then there is an electric field in space aorund it. Or when the electric charge is moving (without acceleration), then it is produced magnetic field in a space around it. Both of these fields permeated to infinity according to Maxwell theory. But how fast...

Homework Statement Determined wave function in a hydrogen atom. ## Ψ(r,θ,Φ) = A(x+iy)e^{ \frac{-r}{2a_0}}## << find A by normalization Answer of a question in my book is ## A = -\frac{1}{a_0 \sqrt{8 \pi}} (\frac{1}{2a_0})^{3/2} ## Homework Equations ## \int Ψ^*(r,θ,Φ)Ψ(r,θ,Φ) d^3r = \int \int...

For this question I want to clarify that 5k which is the electric field component perpendicular to the incident plane ( the xy plane) will be continuous for reflection and refraction , For which none of the options seems correct ,am I right?? The component of magnetic field perpendicular to...

Would not any real measurement taken on a complex state logically require that the results of the measurement have less information than the state? Although I’m just beginning in QM, it appears to me unsurpring that a real measurement on the complex wave function seems to collapse the wave...

Hi. As far as I know, superpositions of waves are normally considered to be waves too, even in dispersive media. But how can they still be solutions of a wave equation of the form $$\left(\frac{1}{c^2}\frac{\partial^2}{\partial t^2}-\Delta\right)u=0$$ if ##c## isn't the same for all of them...

Hi PF, im finishing my bachelor soon and I would really like to do my thesis in De Broglie-Bohm theory. I know its a controversial topic but i refuse to accept the statistical crazyness of qm(i passed qm already). Im not a super good student so I´m asking you for some books on this theory, or...

Hello, I'm trying to write a wave function for a perturbed system. The original (unperturbed) wave function has two solutions for even and odd n-values, for example ##sin(n \pi x)## for even-n and ##cos(n\pi x)## for odd-n. Then, the perturbed wave function also has an even and odd solutions...

Homework Statement *I cannot place the original image due to copyright reasons, but the image above is a good alternative. "Wave crests spread out behind a boat as shown above. What do the wave crests indicate about the boat's speed?" It is increasing. It is less than the speed of the water...

I was studying Feynman Lectures on Physics Volume 1 chapter 29. In there he proves that electric field propagates like a wave. Here is my attempt (in image), please tell me my mistake. Thank you

Is it a fair prediction to state that in the next several years or so, globally, there will be major investments into gravitational wave research, and many more ‘LIGOs’ being developed? Is it a good idea to venture into that area of physics?

Hello all again, I was just thinking again about another aspect of electromagnetic waves: Assume we have a planar wave. How "broad" is it or how far does the electric field of it reach? For instance if we have a single planar wave, assume the k-vector in the direction of propagation and then the...

Just like a concave mirror concentrates light, it can also concentrate sound waves. Ray diagrams like the following look as if all waves converge to a single point of INFINITE power density which of course is not true, probably because of the wave nature of light or sound. What is the correct...

https://ps.uci.edu/~cyu/p224/LectureNotes/lecture7/lecture7html/ Does NaCl have a wavefunction? If so, is it entangled?

If someone wanted to pursue a career in gravitational wave physics, and work at places like LIGO, studying astrophysical objects such as black holes and neutron stars, etc. What are some key courses/skills that person should take/learn as an undergraduate, and graduate student?

Homework Statement A generic state represented by the wave function ##\psi (\vec(x)## can be expanded in the eigenstates with defined angular momentum. Write such an expansion for a plane wave traveling along the z direction with momentum ##p = \hbar k## in terms of unknown coefficients ##c ( k...

Homework Statement For a region where the potential V=0, the wave function is given by ψ(x)=2αsin(3πx/a). Calculate the energy expectation value of this system. Note that α and a are two different constants. Homework Equations ψ(x)=2αsin(3πx/a) E=K+V=K K=p^2/2m ∫ψ*Pψdx=Expected momentum...

Hello Forum, A sound wave intensity (pure frequency) is proportional to the square of the wave pressure amplitude, i.e. ##I \approx p_0^2##, where ##p_0## is the pressure wave amplitude: ##p_0 sin(\omega t \pm kx)##. This means that the (gauge) pressure value goes larger (positive) and lower...

...at the same speed in all directions? Suppose we are an observer floating "stationary" above a body of water moving in a straight line . We drop a weight vertically into the water and cause a wave to propagate out from the point where it meets the water. If we have two additional...

Homework Statement Derive the energy of the standing wave. Homework Equations Standing wave equation: $$y(x,t)=2Asin(kx)cos(ωt)$$ The Attempt at a Solution I am trying to derive the energy of the standing wave. But I am kind of stuck at the approach. Standing wave has no translational...

To start of, I'm new to physics Forums. My thoughts this evening are directed to a physics question. "How to calculate a direction of a wave". The things i believe i need is three sensors that indicates When the wave passes the equipment. I will measure each specific time and compare them...

Homework Statement Consider a particle which is confined in a one-dimensional box of size L, so that the position space wave function ψ(x) has to vanish at x = 0 and x = L. The energy operator is H = p2/2m + V (x), where the potential is V (x) = 0 for 0 < x < L, and V (x) = ∞ otherwise. Find...

Homework Statement A guitar string is vibrating in its fundamental mode, with nodes at each end. The length of the segment of the string that is free to vibrate is 0.381m. The maximum transverse acceleration of a point at the middle of the segment is 8600 m/s and the max. transverse velocity is...

The question is; In an experimental small universe, a photon is released from a source. It continues its path as a probabilistic wave function. if it interacted with mass, we could say the wave function collapsed and observe a particle photon hitting an object. But what happens when the photon...

As I understand space time fabric is exclusively the Gravitational field according to Einstein.So every field wave or interaction is contained in the Gravitational Field.This fabric of spacetime(gravitational field) is having properties of inertia and elasticity that is why gravitational waves...

The answer is B but I don't understand how. Surely, the string at point P is moving upwards. This video gave a solution but the part that they have indicated as down is a different part of the string and not P.

Homework Statement This is Rankine-Hugoniot conditions at a hydrodynamic shock front. Where P2=0 v2=0. The problem is attached. I need to solve a system of equations. I thought it would be relatively straight forward solving for the three unknowns but I'm struggling. I know it's possible to...

I'm a teacher at a Senior High School in Indonesia. I have two Senior High School physics books (Indonesian book) written about simple harmonic motion formula: y = A sin θ = A sin (ωt + θ0) = A sin 2πφ = A sin 2π (t/T + θ0/2π) phase angle = θ = ωt + θ0 phase of wave = φ = t/T + θ0/2π But I...

Homework Statement In the attached file. Homework Equations No equations needed. The Attempt at a Solution I answered it B. Not sure,though. If it is a thick rope the frequency decreses; therefore, the speed decreases.

(1)What is the real cause of refraction? Light wave cannot possible have a change of speed in going onto diffrent medium hence what is going on inside actually that we say its a change of speed. (2) I am notable to comprehend how a change in wavelength not always means a change in frequency. If...

Homework Statement What will be the wave velocity, if a string of 100 cm length is in a 10 kg-wt tension forms 9 nodes when vibrated and becomes symphonic to a 50 Hz tuning fork. Given, Cross sectional area of string, $$A=4.95 mm^2$$ & density, $$d = 0.25 g/cc$$? Homework Equations $$...

Homework Statement the question asks at which point is the string moving upward at the instant shown? Homework Equations No equations needed The Attempt at a Solution I am not sure how I should approach this type of questions. A) will move downward B) downward then upward C) upward then...

Homework Statement A long, heavy rope hangs straight down from a high balcony on an apartment building. The lower end of the rope hangs about 1.0 m above the ground. If you grab onto the lower end and waggle it back and forth with constant frequency f, a wave travels up the rope. What would...

For the half harmonic oscillator the ground state wave function is of the form x*exp(-x^2/2) But sir how to check it's parity and with respect to with point As this function is valid for positive x only Thank you

I am currently reading through 'Optics' by Eugene Hecht chp 2 page 20, he talks about the function of the wave and the direction of travel of the wave i.e ##\psi(x)=f(x-t)## and right at the bottom of the page he say this: Equation (2.5) is often expressed equivalently as some function of ##t -...

There are some things that confuse me about electromagnetic waves, and I haven't found good answers anywhere. Consider the following equation: E=E0 e i(wt-kx) (here E and E0 are vectors, I couldn't find the right symbols). The things that confuse me are the following: 1° We say that the power...

I have seen few examples on Doppler effect and i am confused about one such. We are standing on ground. If the source of sound S moves and Object O is stationary. We would presume the frequency as well as wavelength of sound be changed to the obeject O. But if O moves towards or away from S...