Waves Definition and 1000 Threads

I'm trying to understand how a vibrating body produces oscillations in sound pressure. I've been through derivations and solutions of the wave equation for a string, but I don't understand the transition from waves on a string to sound pressure waves. How are the waves on a string or drum...

Does an accelerating charge, such as one turning a corner emit an em wave or just a pulse? Classical logic dictates it should just be a pulse as there is no oscillation. But which is it?

Is this phenomenon explicable with the simple laws of electromagnetism alone?

If you produced a focused beam from, say, a cassegrain transmitter which consisted of two waves merged but one inverted what would be the result. I presume there would be destructive interference. My question is, where does the energy go?

Hello all, - first of all sorry for my bad english, it's not my mother tong. - I write here because I want to understand that are the surface waves and how can we demonstrate their existence ? Do you have a PDF file which speak about this ? - For volumic waves I have seen a mathematical...

In images I always seen pulses as a part of a wave corresponding to an half of a piece of wave, but it is called still a pulse when we have a part with a complete wavelength? I mean this (in the photo) And what the difference between waves and pulses? What I think is that is still a pulse...

Homework Statement Given two waves characterized by y1(t) = 3 cos wt; y2(t) = 3 sin(wt + 60deg); does y2(t) lead or lag y1(t) and by what phase angle? Homework Equations y1(t) = 3 cos wt; y2(t) = 3 sin(wt + 60deg) The formula I'm given in my book Fundamentals of Applied Electromagnetics is...

Why does sound waves propagate trough space with areas of lower and higher pressure, why does not pressure just equalize without waves? Thanx for answers.

Homework Statement Sound waves can be refracted when they travel through balloons filled with different gases. How would the motion of a sound wave be changed if it traveled through a balloon filled with carbon dioxide?BOOK ANSWER "Being more dense than air, the carbon dioxide in the balloon...

Homework Statement Q Provide an explanation for the following statements. [/B] STATEMENT 1 The captain on an ocean ship is proceeding slowly into waves coming towards the ship. He notices that the waves change in two ways about 200 m ahead of where the ship is located. The waves get...

Homework Statement What happens to the wavelength, frequency and amplitude of the water wave when it travels from deep to shallow water at an oblique angle to the normal? Homework EquationsThe Attempt at a Solution The wavelength will decrease. The frequency will be unchanged because the...

Can gravitational waves be treated like light or water waves? E.g. what would happen if two waves intersected at their max amplitude? Or what would happen if they intersected at a peak and trough?

Homework Statement Why can’t transverse waves travel through a gas or liquid? Homework EquationsThe Attempt at a Solution I understand that transverse waves require rigid medium through which to transfer their energy so they can travel through solids. I'll just accept that transverse waves can...

What's the solution to the wave equation for circular waves on a two-dimensional membrane? The waves have a constant wavelength throughout. For spherical waves, you have to multiply the amplitude by 1/r. I tried 1/√r for circular waves but it didn't work. :blushing:

the equation for wave velocity is velocity = wavelength * frequency. now by using the Doppler equation for change in frequency and the Doppler equation for change in wavelength. if you multiply those two equations together you get. frequency' *wavelength' = original frequency * original wavelength.

Homework Statement Calculate electric field and magnetic field produced by radiation emitted by a 100 W bulb at a distance of 1 m if radiation efficiency is only 5%. Homework EquationsThe Attempt at a Solution I only know how to find intensity due to the bulb: I = P/4πr2 = 5/4π W/m2 I have...

Hi i've been taught that standing waves do not transfer a net energy. but standing waves are formed in instruments, and we can hear them - so some sound energy/kinetic must be transferred to surrounding particles to reach our ears? how does this work? please could you help me if my understanding...

what are cosmic waves and radio waves made of? What's the difference between the two? Can waves like them transfer energy ?

Moderator's note: this post follows from the Is light a wave or a particle FAQ Nothing to add, rather just a query. 1) Do Photons move in a wavelike manner, as given by De Broglie's Equation? 2) If so, will the wavelength obtained over there be different from that of the electromagnetic wave...

Ive been wondering about this for about two days and i have a simple question and that is , if I have two photons that are 180 degrees out of phase, passing through a surface perpendicular to the photons velocity vector then will the EM fields exert tension on the surface?(in this case the...

Homework Statement The linear mass density of a non-uniform wire under constant tension gradually decreases along the wire while ensuring an incident wave is transmitted without reflection. The wire has constant density μ for x ≤ 0. In this region a transverse wave has the form y(x,t) =...

A suspension bridge oscillates with an effective force constant of N/m. (a) How much energy is needed to make it oscillate with an amplitude of 0.106 m? (b) If soldiers march across the bridge with a cadence equal to the bridge's natural frequency and impart J of energy each second, how many...

Hello, I am trying to find the magnetic field that accompanies a time dependent periodic electric field from Faraday's law. The question states that we should 'set to zero' a time dependent component of the magnetic field which is not determined by Faraday's law. I don't understand what is...

ELF electromagnetic radiation is in the range of 3 to 30 Hz. If you had a 3Hz ELF laser pointer and you had a camera that could "see" ELF, would you be able to see the intensity of the beam "flicker" at 3Hz?

hi every one can anyone give me a course or a paper talking about the four waves formalism introduced by Landau and Lifshitz thanks for advance :)

Hello, I was wondering if anybody knew of any material (books, papers etc..) which considers a possible connection between longitudinal waves and vector potentials, at least mathematically. I have been scouting about, but failed to find anything substantial. I understand that there seems to be...

My understanding of electromagnetic radiation is this: When a charged particle accelerates, there is a change in its associated electric field at all points in space, though not instantaneously. The "electric field wave" is basically the propagation of the disturbance that occurs when the...

Homework Statement By adjustin her lips correctly and blowing with the proper pressure, a bugler can cause her instrument to produce a sequence of tones, amog which are the following: 440, 660, 880, 1100, . . . Hz --- all without changing the length of the air column. (b) What is the ffective...

Homework Statement You are designing a thin transparent reflective coating for the front surface of a sheet of glass. The index of refraction of the glass is 1.52 and when it is in use, the coated glass has air on both sides. Because the coating is expensive, you want to use a layer that has...

Homework Statement A diffracting grating casts a pattern on a screen located a distance L from the grating. The central bright fringe falls directly in the center of the screen. For the highest-order bright fringe that hits the screen, m=x, and this fringe hits exactly on the screen edge. This...

I have three doubts in regard to waves on a string which I will try to make as clear as possible. For this purpose, I have considered a general wave: $$y_i=y_0\sin(\omega t - kx)$$ (1) If a wave pulse: $$y = y_0 e^{\frac{-1}{T^2} \left(t-\frac xv \right)^2}$$ is incident against a rigid...

Homework Statement Given that high tide occurs twice each day. What is the tidal frequency in Hz? Homework Equations frequency in Hertz = no. of complete cycles per second The Attempt at a Solution Since the there is only one wave cycle between 2 high tides Frequency=1/(24x3600) 4. My...

Hey, I have a question about waves. Why is it that the energy of a wave depends only on the frequency but not on the wavelength? Shouldn't two waves that have the same frequency but different wavelengths also have a different energy? If not there should be some other quantitiy with which one can...

Homework Statement I am just wondering is there any apparatus available to produce EM waves of arbitrary wavelength and intensities? If not, how I can produce an EM wave of my desired wavelength in the laboratory? Homework EquationsThe Attempt at a Solution I completely have no idea :(

Is there any star systems (planetary) that are influenced by the EM Force, hence as usual,sum of the charges of elements in the universe are electrically neutral.

Geroch 1968 touches on the Kundt type I and II curvature invariants. If I'm understanding correctly, then type I means curvature polynomials. Type II appears to be something else that I confess I don't understand very well. (I happen to own a copy of the book in which the Kundt paper appeared. I...

scientists have observed light acting as waves on a macroscopic scale before the quantum characteristics of particles were discovered. My question is what sets apart the macroscopic wavelike characteristcs of light apart from other matter waves? This may be a stupid question but can the...

In the propagation of non-monochromatic waves, the group velocity is defined as v_g = \displaystyle \frac{d \omega}{d k} It seems here that \omega is considered a function of k and not viceversa. But in the presence of a signal source, like an antenna in the case of electro-magnetic wave or a...

What happens to a body experiencing a gravitational wave? Suppose I put a ball in the path of a GR wave. As the wave passes through it, the space will expand and contract. This means that the space between every point in the ball should expand and contract. But what will be the reference point I...

Homework Statement Hello, I've recently started learning about waves, and there are a few stuff I don't understand (I'm talking about transverse waves):1. What function describes the movement of a single "element" on the string? I mean an element in which only its y changes, but x remains...

Hi, so I have this question: A wave pulse on a string has the dimensions shown in the figure (Figure 1) at t = 0. The wave speed is 40 cm/s. a) Draw the total wave on the string at t=15ms, 20ms 25ms, 30ms, 35ms, 40ms and 45ms. b) repeat part (a) for the case in which the end of the string is...

Please correct me or excuse me for my potential ignorance but why do waves oscilliate?

In the full internal reflection case where we have a refracted evanescent wave, If another object is nearby, then we could have wave tunneling phenomenon(frustrated total internal reflection). 1) So, how can the evanescent wave which does not transfer any net energy produce another wave at the...

Suppose we have two laser diodes that are made to transmit light at the same wavelength and intensity. Also, suppose that we place them in an open space and separate them by a distance such that when their generated beams intersect at one point in space and one point only. Further suppose that...

Is there an easy explanation of total internal reflection of light using Quantum mechanics(or QED)?

Hello! My name is Nick and I have an MSc in Computer Science, I'm also Physics enthusiast and amateur/independent researcher. I would like to ask for your help on something. I'm currently trying to find a way to study ultrasonic waves' effects on water and I'd like to find a means of...

Homework Statement A ski gondola is connected to the top of a hill by a steel cable of length L and radius R . As the gondola comes to the end of its run, it bumps into the terminal and sends a wave pulse along the cable. It is observed that it took T seconds for the pulse to return. What is...

Homework Statement The problem I have is that we are asked to show the complex relative permittivity of a good conductor is erc = 1 + i(sigma)/(omega*epsilon_0) where sigma is the conductivity and omega is the frequency of an electromagnetic wave in the medium. This is fine, I calculated it...

Homework Statement Homework EquationsThe Attempt at a Solution I formed a right angle triangle between the arrow downwards,d, and perpendicular line x from arrow. As such, sin θ = x/d. x= d sinθ path difference: d sinθ/λ My answer is C, but answer is B. Where did cos θ come from?

When finding solutions to Maxwells equations we always cosider the case of a plane wave. But are plane waves real/physical solutions we can consider in real life? My guess is not because it is required to propagate infinitely. So why do we use plane waves to solve Maxwell's equations?