Waves Definition and 1000 Threads

Hi there! I am currently building a simulation to model the propagation of radio waves in seawater in terms of its propagation loss. I have previously discussed the models I've looked at but have settled on a model which depends primarily on the propagation distance ##r##, the carrier wave...

For electromagnetic wave if it's reflected from a perfect conductor standing wave can be form. I wonder why Poynting vector can be used to describe the intensity of standing EM wave. (see p.19 of http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide13.pdf ). From some textbooks...

According to Max planks equation, E=h*f, the more is the frequency the more is the energy of the EM waves. So why UVC (shortest uv ray or high frequency uv ray ) is absorbed by the ozone and UVA and UVB rays ( longer uv rays than UVC penetrate the ozone and reach the Earth's surface?

Homework Statement 40-cm long string, with one end clamped and the other free to move transversely, is vibrating in its fundamental standing wave mode. If the wave speed is 320 cm/s, the frequency is[/B] A 16 Hz B 8 Hz C 32 Hz D 2 Hz E 4 Hz Homework...

Before I start, I apologise for the information dump that is to follow. I don't expect all questions to be answered or all models to be addressed; I simply feel it is appropriate to provide the community with my current knowledge and stage of research so you may not have to search for it...

Homework Statement 1)Find the EM fields that go through a coaxial waveguide (inner radius equals a, outer radius equals b) filled with a dielectric material where both TE and TM modes propagates. 2)Find the cutoff frequency. 3)Find the cutoff frequency if we close both ends of the waveguide...

I am told that even macroscopic objects like footballs obey the wave equations of quantum mechanics. Is there any experimentally based reason to believe this, or is it just said as a way of generalizing the theory?

Would it be possible to use diffraction to focus the enrgy of sea waves, on the principle of the zone plate (https://en.wikipedia.org/wiki/Zone_plate) but reduced to 2 dimensions? This could be done by an array of wave-opaque objects such as floating breakwaters, particularly along coasts...

Considering a plane wave propagating in one specific direction, does its wave vector dependent on a certain point in the plane wave or is it dependent on a certain point on a plane parallel to the wave?

Hello, I have the configuration as shown in attached picture. I know how to calculate string tension and measure frequency if the string is not moving. But what happens if the string is moving at a constant speed? Are there still standing waves? Can we still calculate the string tension? What if...

I want to have a simple and intuitive explanation of why the sin and cos waves have such a simple repetitive values for their derivatives at a specific point. Their derivative values are also periodic in respect to the derivative order. For example, e^-x is also periodic, but its derivatives are...

Shock wave is caused by the disturbance of air by the airplane. When it propagate the mechanism should be the same as that of longitudinal sound wave. Why sometimes it can travel faster than sound? (also see: http://physics.info/shock/ )

Homework Statement Homework Equations dsinθ =nλ The Attempt at a Solution I don't understand why an interference pattern will only be observed along XY only. Why don't the waves intersect along RS. Does it have something to do with R being the midpoint of PQ?

Sources A and B are on the horizontal x-axis and both emit a long-range radio wave of wavelength 400m, with the phase of emission from A ahead of that from source B by 90 degrees. The distance r(A) from Source A to the detector (D) in the y-axis is greater than the distance of r(B) by 100m. What...

In deriving wave equation or power transmission of wave transmitted by a string, it is usually stated (with some assumptions) that the transverse force on a point of the string is proportional to the slope at that point. An example is given in p.20 of this notes...

In the attached figure, light is incident at angle $${\theta}_{1} = 40.1^{\circ}$$ on a boundary between two transparent materials. Some of the light travels down through the next three layers of transparent materials, while some of it reflects upward and then escapes into the air. If $${n}_{1}...

http://www.elateafrica.org/elate/physics/waves/traqnsversewaves.jpg Note that : Leaf. A has attained maximum displacement and is about to start going down .Leaves B, C and D are still going up. Each of them will finally attain its maximum displacement and then move downwards to complete the...

I am curious on what is meant by amplitude in an EM wave. From all the searching I have done the amplitude has something to do with the density of photons in the EM wave, and the frequency with energy of the photons. The part I am confused about is the fact that the wave is oscillating. I...

Correct me if I'm wrong, but based on what I've learnt, there are three kinds of waves: mechanical, transverse progressive and longitudinal progressive. Mechanical - A disturbance makes particles vibrate on the spot Transverse progressive - Energy is carried, and moves perpendicular to the...

I've found this a very confusing thing:when we locate the second dark fringes above and below the central maxima,we divide the slit into four parts and claim that pairs of waves interfere destructively as the path difference would be wavelength/2.But what if we just divided it into two parts and...

To motivate the question, Andy Strominger recently put out a paper on calculating the Sagnac shift of counterrotating beams due to the angular momentum flux of a passing gravitational wave. See here: http://arxiv.org/abs/1502.06120. But consider now two nearby freely falling gyroscopes...

Hello, I've searched the internet for an answer to this question but cannot find it. Not a homework question, I'm just designing a recorder and don't understand this. A recorder is a fipple flute, meaning that it generates standing sound waves by finger placement over holes that change the...

I heard that the analysis of wave measurements close to shore verifies that as long as wave amplitudes are small with respect to mean depth a Rayleigh distribution remains satisfactory of wave heights, but how ?

Homework Statement [/B] A student uses an audio oscillator of adjustable frequency to measure the depth of a dried up well. Two successive resonances are heard at 17.0Hz and 23.8Hz. The speed of sound in air is 343 m/s. How deep is the well?Homework Equations f=nv/4L The Attempt at a Solution...

I would like to obtain the conformal map from a uniform rectilinear fluid flowing in the x-direction, where the field is bounded below by the x-axis, to the flow in the w-plane. In the w-plane the flow is correspondingly bounded from below by a trochoid. (A trochoid is a continuous waveform...

I have one question. Charge density waves are usually defined as phase transitions on metal in which electrons started to behave like collective. Is this happen always in quasi one dimensional metals? Also why this transition actually happens?

Homework Statement A public-address system is usually used in the school assembly to obtain better attention from students. Carry out a study on the factors affecting the audibility of sound. Homework EquationsThe Attempt at a Solution Objective: To study how does the frequency of the sound...

Homework Statement One microscope slide is placed on top of another with their left edges in contact and a human hair under the right edge of the upper slide. As a result, a wedge of air exists between the slides. An interference pattern results when monochromatic light is incident on the...

Hello. So I am having some trouble answering this question and I would really appreciate some help. I figure I should probably first define what standing waves are and I know that they are the result of the repeated interference of two waves of identical frequency while moving in opposite...

Of the few occasions I've seen Airfoil Lift described to general audience (on documentaries), it has focused on the top-side curve of the Airfoil causing air on the topside to move faster than the bottom-side. This is said to reduce air pressure on the topside and result in lift. If a wave is...

Homework Statement A sound source is placed at the top of a tall (h = 189.6m) radio tower. The source has a frequency of 740 Hz and an amplitude of 19.4 nm at point A. The air surrounding the tower has a density of 1.29 kgm-3 and sound travels through it with a velocity of 343 ms-1. Point A is...

Hello folks. This is Sandeep. I have many lingering doubts in physics that I am here to get cleared. This has become more of an issue ever since I decided to teach physics to my young nephew. My first question pertains to electromagnetic waves and the conservation of energy. Consider an AC...

Hi, My problem is with A.P. French vibrations and waves question 3-10, part (b). Question 3-10(a) A metal rod, 0.5 m long, has a rectangular cross section of area 2 mm2. With the rod vertical and a mass of 60kg hung from the bottom, there is an extension of 0.25 mm. What is the Young's...

http://www.quora.com/How-can-sound-waves-alter-the-flow-of-water Ok, so I carried out this experiment, and I understand some of it, but need help with other parts. Ok, so are we actually seeing a sine wave formed by the water? If so, I understand that waves are supposed to transport energy...

nothing in the universe moves without force, so what does makes em waves move through space?

Homework Statement Serway's Physics for Sciencetists and Engineers with Modern Physics, 9th Edition (current), Chapter 16, problem 19:[/B] (a) Write the expression for y as a function of x and t in SI units for a sinusoidal wave traveling along a rope in the negative x direction with the...

Homework Statement A woman drops a stone into a well 180 m deep. If the air temperature is 20 oC, how much time will elapse between the moment the stone is dropped and the moment the sound of the stone hitting the bottom of the well is heard? [6.6s] [/B] Homework Equations Vsound = 331.4 +...

1. a source of sound is directed a large brick wall. a girl walks towards the wall and notices that the intensity of the sound decreases to aminimum every 50cm. what is the frequency of the sound? the air temperature is 20 degrees celsius (answer is 344Hz)2. attempted to use the universal wave...

Problem: A swimmer sees a parachutist hit the water and hears the impact twice, once through the water and the second time through the air, 1.0s later. How far from the swimmer did the impact occur. Vs of air is 340m/s. Vs of water is 1400m/s and the answer in the book is 450m. 2. I know this is...

I understand that sinusoidal EM waves result from charged particles in harmonic motion, e.g., up and down an antenna. But what if the charge is undergoing some more complicated periodic motion? Wouldn't the EM waves be non-sinusoidal? I saw in a textbook a hypothetical EM wave with infinite wave...

Homework Statement Two slits are separated by a distance of 4.40x10-6m and illuminated with two monochromatic light sources with wave lengths of 600nm (red) and 400nm (violet). The mr bright fringe of the red light coincides with the mv bright fringe of the violet light. What are the lowest...

Homework Statement Calculate the room temperature by using the speed of sound formula and using the given values. Known Data: Frequency = 480 Hz 2nd Resonant length = 54cm or 0.54m Homework Equations v = 331 + (0.60)T T = (v - 331)/0.60 v = fλ (Open-Closed air column) L = (3/4)λ The...

Homework Statement 560 nm light is collimated and passes as a parallel beam in a direction perpendicular to the ##x+y+z=0## plane. It is polarized parallel to the ##(y-z)## plane. Treating it as a plane wave, what are the real E and B fields? Intensity of the beam is ##1 \ mW/cm^2##. Make...

I have a question about complex reflection and transmission coefficients. For example, I am modeling a wave in air (medium 1) ## \varepsilon = \varepsilon_0 ## reflecting on, and transmitted to, a medium 2 with ## \varepsilon = \varepsilon' -j \varepsilon'' ## If the wave would have traveled...

I have coils to transmit and receive the power supplied.When we supply the transmitter , it omit the electromagnetic wave.Does it omit one electromagnetic wave or a lot of them? If there are several of them, is the energy supplied ,divided equally to the number of waves or every wave carries the...

I am reading through my course guide and problems worked out and something bothers me. I think at this point we are working with classical waves, moving towards QM eventually. The idealization we work with is this. We have a light source creating a wave ψ(x,t)=Acos(ωt+kx) . The light beam...

Hi All, Kindly see the attached Pictures. I think COB is not 90 - δ/2 But COB is 90-δ Can someone confirm. Thanks.

What's the matter: So, I think I have some skills when it comes to differentiation after taking calculus 2 last semester, but when it starts to intertwine with physics, and interpreting physical phenomenon through equations, It appears I could use some help. Anyway, the problem that I got hung...

%PLOTTING TIME DEPENDENT MOTION OF A STANDING WAVE %Define Parameters a_n = 1; k = 5; w_n = 5; x = 0:0.05:4; t = 1:0.05:20; for j=1:length(t) for i=1:length(x) u(i) = a_n*sin(k.* x(i)).* cos(w_n.*t(j)); %Formula for displacement end pause (0.1) plot(u)...

Is there a theoretical way to force electromagnetic waves transfere energy point to point like electricity instead omni-dirrectionally? I think it might be helpful for looseles wireless energy transfere.