Wave Definition and 999 Threads

I have asked a form of this question previously: https://www.physicsforums.com/threads/electromagnetic-waves-and-polarity.857347/ ...but have come back to it in slight confusion. Say I have this antenna and the voltage source is increasing with a constant acceleration of its voltage. It...

Hi, it is well known that spontaneous emission of an atom can be enhanced, if the atom sits at a node of the vacuum standing wave field in a cavity. My question is, why is it the node? At a node of a standing wave, there is zero intensity, so there should be no interaction between the atom and...

Why does a wave function collapse when we observe a particle? I would like to know why something that is in Super Position suddenly chooses a particular position when observed? If something is in all positions or states. How does the particle choose a particular state? What is the decision...

Homework Statement Homework Equations General wave solution y=f(x+ct)+g(x-ct) [/B] The Attempt at a Solution [/B] Graphical sketch

Hi, Simple question, sort of: I see that according to the internet the mathematical description of a triangular wave is rather complex, so I'll try to stay as far away from that as I can, because I'm a bit rusty. I understand that if you integrate a square wave you get a triangular wave on the...

The combination of a half-wave plate followed by a polarizer is commonly used as a variable attenuator for polarized lasers. The idea is that the beam enters the half-wave plate, and you rotate the half-wave plate leading to a rotation of the polarization direction of the beam. As the beam is...

Hello all, I am doing this question where it asks if I increase the tension of a two loop standing wave without changing the frequency, what kind of standing wave will I get? I came to the conclusion that it would become a one loop standing wave as f= 2L/(n) as I plugged in 2 for n and I got...

So my question is, how does this work (hopefully I'm allowed to do hyperlinks): https://www.desmos.com/calculator/zlvrts7mul Given a table of x and y coordinates, how do I find the sin wave of best fit. I need to get f (frequency), a (amplitude), and p (phase) for the function in this form f(x)...

Homework Statement [/B] Ignore the suggested Problems if you will. If you can't see the image give me a shout and I'll give the problem statement here. Homework Equations B(y,t)=Bmaxcos(Ky-Wt) Wavelength=2pi/kn W=2pi*Frequency V=Emax/Bmax V=Walength*Frequency The Attempt at a Solution So...

Relative to the observer, objects shorten when approaching the speed of light exponentially. Does this rule also apply to the wave function? Does this rule also apply to massless particles like Photons? Or am I just simply forgetting something?

When a light bulb is emitinting light, is there a continuous wave spreading out, or is there a large number of particles (photons) emitted in random directions, which in the conglomerate, mimics a single continuous wave spreading out.

Homework Statement An electromagnetic wave with the frequency f = 1.4 GHz is propagating in the z-direction from vacuum in a plasma with the magnetic field B_0 = 0.1T z^. The plasma density is 1.0*10^17 particles/m^3. The wave is the separated into a R- and L-wave in the plasma. Homework...

Hi all, Is there any way to impart a transformation upon a radio wave's reflection from an object, such that the reflected wave is different from the original signal in some way (frequency, phase, etc.)? Not sure what this would require (maybe a constant and active coordinated interference...

I heart from my friend that light is both wave and particle but i don't know that is true or not. So can you guy tell me what light actually is? And how light travel from the source and then to our eye?

I know that if the intensity of a light beam with of a certain frequency varies it means the number of photons the light beam is composed of varies and not the individual photons energy. That would mean the E and B field amplitudes vary. This would mean that that the amplitudes of the E and B...

Hello. I'm not sure if this question is to project-specific, but I will try to explain as best that I can. I am working with a system such as this one, with only a few differences: http://www.sciencedirect.com/science/article/pii/S0168583X1400706X it is a cryogenic stopping cell. The part I am...

Say you were building a full-wave rectifier. How many simple ways (if any) are there to reduce the THD on the source caused by using a full-bridge rectifier load? Also, If you used a low pass filter and then an isolation TX (or the other way around?), how much would that help to this end (if at...

The classic limit of Schrodinger equation is hamilton-jacobi eqution. Wave function's classic limit is ##\exp{\frac{i}{\hbar}S(x,t)}##,##S(x,t)## is the action satisfying hamilton-jaccobi eqution. However, a particle travels along single trajectory of ##S(x,t)##, Why not make some constrains...

Hi, i am looking for a general form of a wave equation in a medium. i am not looking for a concrete physical equation but rather a generalized form (preferably in n dimension) of such under the simplest assumptions (it's of course a little equivocal what 'simplest' means but, well). so for a...

Homework Statement y1(x,t) = 5.00sin(2.00x - 10.0t) y2(x,t) = 10.0cos(2.00x - 10.0t) a) Prove that the wave that is the result of the superposition is a function of sin. b) What's the phase angle and amplitude of said wave? Homework Equations y = y1 + y2 The Attempt at a Solution...

Note: added to the title should be "and a particle description". ## \\ ## The intensity (energy density) of an electromagnetic wave is proportional to the second power of the electric field amplitude, i.e. intensity ## I=n \, E^2 ##, apart from proportionality constants. Meanwhile the energy...

A body is reentering the Earth's atmosphere at a Mach number of 20. In front of the body is a shock wave. Opposite the nose of the body, the shock can be seen to be normal to the flow direction. Determine the stagnation pressure and temperature to which the nose is subjected. Assume that the air...

Homework Statement There's a string with tension T & mass density μ that has a transverse wave with ψ(x,t) = f(x±vt). f(x) is an even function & goes to zero as x→±∞ Show that the total energy in the string is given by ∫dw*T*((f'(w))2; limits of integration are ±∞ Homework Equations The...

So I am just working with a synth and I am having it create a single sine wave. I am then looking at the output on a db vs frequency graph and I would expect the db to only be reading at the frequency of that sine wave, but there are readings from 20 Hz all the way to 2k Hz sometimes(althought...

Homework Statement A ship floats across the coat, at a distance d = 600 m from it. The radio of the ship receives simultaneously signals of the same frequency from RadioTowers A & B, which are L = 800 m apart. At Point G (Γ), the two waves confluent in a strengthening way, where G's (Γ)...

Homework Statement Two identical speakers, 10.0 m apart from each other, are stimulated by the same oscillator, with a frequency f, of 21.5 Hz, at a place where the speed of sound is 344 m/s. a) Show that a receiver at A will receive the minimum intensity of sound (Amin) due to the...

Hi, I'm recently reading something which briefly introduces C symmetry. So the thing that confuses me is that how does the spatial wave function contribute the (-1)^L factor? Thanks!

Homework Statement A transverse wave that is propagated through a wire, is described through this function: y(x,t) = 0.350sin(1.25x + 99.6t) SI Consider the point of the wire that is found at x= 0: a) What's the time difference between the two first arrivals of x = 0 at the height y =...

We know that a wave is represented by f(x - vt) and it follows the differential wave equation. e^(x - vt) satisfies both the condition. But is it really a wave? Because to sustain the wave we need infinite energy which is not possible. So what's happening here?

Homework Statement A mass of 120 g rolls down a frictionless hill, reaching a speed of 4.2 m/s. This mass collides with another mass of 300 g that is at rest and attached to a spring with constant 30 N/m. The two masses stick together and enter into periodic motion. What is the equation for the...

Homework Statement given: A wire loop with a circumference of L has a bead that moves freely around it. The momentum state function for the bead is ## \psi(x) = \sqrt{\frac{2}{L}} \sin \left (\frac{4\pi}{L}x \right ) ## find: The probability of finding the bead between ## \textstyle...

I am a beginner in quantum mechanics. I started out with D. J. Griffiths' book in quantum mechanics. I'm having a problem in understanding the wave function. What is the physical meaning of the wave function? I searched on the net but didn't get any good explanation. I understand that the...

Homework Statement A guitar string with 0.60 m and 0.012 of mass vibrates with frequencies that are multiples of 109 Hz. Approaching to the string a tuning fork of 440 Hz we verify beats between the sound signals of the string and the tuning fork. Calculate the time interval between consecutive...

If you know where to look for an electron (e.g. in an atom or an experimental setup) it is quite understandable that, until you know exactly where it is, there is a calculable probability of where it might be. However, if we take the case of an un-associated electron in space, it would seem that...

Could a particle move through and displace a Bose-Einstein condensate, causing it to wave?

Homework Statement Suppose a tube is filled with helium gas at a pressure of 0.11MPa and a temperature of 297K. If a piston of area of 400mm2 at one end of the tube creates sound by moving sinusoidally with a frequency of 60Hz, creating a wave with amplitude of 3.8mm, what power goes into (I'm...

Also, if you get the gist of what I am asking, I would greatly appreciate correction of my vocabulary.

An atom of oxygen can be suspended in air, yes? Can a wave be suspended independently? Or does it need to be generated?

Hello! I am reading some introductory stuff on Klein-Gordon equation and I see that the author mentions sometimes that in a certain context the K-G equation "is a classical field equation, not a quantum mechanical field equation". I am not sure I understand. What is the difference between the...

Hi! 1. Homework Statement From the website http://www1.uprh.edu/rbaretti/MomentumspaceIntegration8feb2010.htm we can see the Fourier transform of the ground state hydrogenic wave function : Φ(p) = ∫ ∫ ∫ exp(-i p r) (Z3/π )1/2 exp(-Zr) sin(θ) dθ dφ r² dr (1.1) After intregation...

Homework Statement In Griffiths' book "Introduction to Quantum Mechanics", Section 2.3, Chapter 2, the Fig. 2.7 gives the plots of the wave function (##\psi_{n}##) and its modulus of the harmonics oscillator, see the Appendix. With the order (##n##) increasing, they become both higher. However...

This animation demonstrates a longitudinal wave by means of moving bars. I realized that if we increase the amplitude of the wave, the bars will eventually start passing through each other, which sounds (no pun intended) like an unphysical scenario. Does this mean that there is a cap, a...

In the 1930s, John von Neumann consolidated ideas from Bohr, Heisenberg and Schrodinger and placed the new quantum theory in Hilbert space. In Hilbert space, a vector represents the Schrodinger wave function. I know they are equivalent.. But can we say it is more natural and intuitive to say...

Homework Statement A wave is shown below. The dots represent the particles of the wave at a time t = 0 s, and the vertical lines represent the positions of the particles before the wave arrives. Find the amplitude and wavelength of the wave Homework Equations Not sure The Attempt at a...

hey So Fourrier transform is ##f(t) = \frac{1}{2 \pi} \int_{-\infty}^{\infty} F(\omega) e^{i \omega t} d\omega## with ##F(\omega) = \int_{-\infty}^{\infty} f(t) e^{-i \omega t} dt## Question 1 - The Fourier mode for the continuous case is ## \frac{1}{2 \pi} F(\omega) e^{i \omega t}##, is...

In the Great Courses lecture series "Oceanography", Prof. Tobin says that the general direction of beach sand movement ("sediment transport") along both the east and west coasts of the USA is from north to south. On the east coast, this is because the prevailing direction of waves is from the...

https://www.nature.com/search?journal=nphys&q=wave%20particle%20duality&page=1 When people come to this forum enquiring about the concept of wave particle duality the usual advice seems to be based on the idea that the concept is outdated and has historical interest only. The problem is that...

For using Galilean transformation, I have to assume that speed of light w.r.t. ether frame is c. W.r.t. ether frame, E = E0 eik(x-ct) W.r.t. S' frame which is moving with speed v along the direction of propagation of light, E' = E0 eik(x'-c't') Under Galilean transformation, x' = x-vt, t' = t...

Hi PF! Suppose we have a water wave with mean depth ##H## with disturbance ##\zeta## above/below ##H## propagating through a channel of thickness ##b##. The book parenthetically remarks that the continuity equation becomes $$\partial_t(b(H+\zeta))+\partial_x(bHu)=0.$$ However, when I try...

A system of |1> and |2>, in the beggining has a function |Ψ(0)>= cosa|1> + sina|2>. The energy of the system is; https://i.imgur.com/I0C7BFg.png a, ε,n are known. Find the |Ψ(t)> The solution is; https://i.imgur.com/urWs6XW.png It is known that; |Ψ(t)>= e^(-iHt/ħ) * |Ψ(0)> but I don't...