Propagation Definition and 457 Threads

  1. I

    Need clarification on sig-figs and propagation of error.

    Hello, I have a question asking me to find the volume of a rectangular prism. The dimensions are as follows: x = 20 ± 0.2 cm, y = 30 ± 0.2 cm, z = 70 ± 0.4 cm I am asked to report the answer with the correct number of significant figures and include the error. What I have so far: V = xyz =...
  2. 24forChromium

    What is the relationship between T2 and T1 in torque propagation?

    See image. If T_1 and L is known, what is T_2? (T_2 is caused by T_1)
  3. N

    Can a Blast Wave in a Pipeline Outrun HMX Detonation Velocity?

    I'm a little rusty on my physics, so here's the hypothetical: Put HMX prima cord in a long pipeline , say 1000m. If you detonate the prima cord and the pipe has a 3" ID, would the blast wave outrun the HMX detonation velocity of 9100 m/s. If you reduced the ID of the pipe, is there a certain...
  4. F

    Wave propagation with water moving

    Homework Statement Suppose a person is fishing and is bobbing the fishing pole in constant intervals, there are 2 fish in the water located in the same distance L from the fishing pole (the source of the wave). Suppose also the water is moving from A to B. Which fish will feel the wave first...
  5. O

    Unit conversion - stress-wave propagation speed

    Dear Friends, The stress-wave propagation speed is calculated using : sqrt (elastic modulus/density) The unit of elastic modulus is GPa, and that of density is gram/cm^dim Can anyone please tell me how I can convert the resulting value to m/s (meter/second)? Regards
  6. Jacekmai

    Electric current propagation through living tissue

    Wave propagation speed or velocity of propagation (VoP) of a transmission medium is ratio at which the wavefront of the signal passes through the medium to the speed of light in vacuum. For example, copper has a wave propagation speed ~0.951. What is a wave propagation speed through a living...
  7. T

    Error propagation when using modulus operator

    Sorry if the answer is very simple, but I just had a question regarding error propagation when using a modulo operator in intermediate steps. For example, I have ## \theta = arctan(\frac {A}{B}) ## and then I do ## \theta ## % ##2\pi## (modulo ##2\pi##). This gives me an answer between ##...
  8. H Smith 94

    Understanding propagation loss: What does this output mean?

    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...
  9. H Smith 94

    How is radio wave propagation modelled in seawater?

    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...
  10. S

    Wave frequency and propagation attenuation

    In my memory, the wave frequency will decrease because the attenuation in wave propagation, is that true? Can someone please give me some links to prove or disprove it? thanks
  11. ddd123

    Aharonov-Bohm information propagation

    I hope I've searched the forums thoroughly enough, I didn't find a similar question. I'm wondering about the specifics of the speed of the information on change in B of the solenoid between the two paths in a double-slit setup, one large enough where relativistic speed effects are within a...
  12. P

    Error Propagation with Log2 Concentration: Fluorescence Measurement

    Hi there, I have a quick question to report some numbers on an experiment. I made measurements of fluorescence in a titration of a chemical. The titrations were 1:2 serial dilutions so I report each fluorescence as a function of the log2 concentration: concentration chemical x: 1 , 0.5, 0.25...
  13. Gh778

    Delay of propagation of the pressure in a fluid

    Homework Statement Does the delay of propagation of pressure gives a torque during a short time ? A disk full of a liquid turns at a constant angular velocity w around the red axis. At a time, a valve move out, this will increase quickly the pressure inside the liquid. 1/ Draw the lines...
  14. S

    Electromagnetic waves point to point propagation

    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.
  15. Aristotle

    Finding the Uncertainties in Frequency with Given Capacitor and Inductor Values

    Homework Statement I am given a frequency value of 95 GHz (9.5x10^10 Hz), C= 25 F, L=1.12x10^(-25) H. The question is to find the uncertainties in frequency by taking account of inductor being 5% accurate & capacitor being 8% accurate. Homework Equations I believe this is the correct formula...
  16. H

    Finding propagation speed/wavelength from an equation

    Homework Statement A wave is described by y=12sin(4t-8x). What is its propagation speed? A. 0.2 B. 0.5 C. 4 D. 8 E. 12 Homework Equations v=wavelength/period v=wavelength×frequency The Attempt at a Solution period= 2π/w=2π/8=.7853 But confused on how to find the wavelength?
  17. J

    Acoustic Impedance - Ultrasound Propagation in Tissue

    Hi, I was just wondering why, when the acoustic impedance mismatch is so high between two boundaries at an interface, most of the ultrasound is reflected back. I was just wondering why this happens which I can't seem to find much of an answer to. The only thing I can think of is refraction and...
  18. I

    Error propagation - partial derivative?

    I am getting a little confused on which error propagation to use: I am looking to calculate the error in B*Cos(θ) , for the vertical axis of a williamson hall plot. where B is fwhm of a peak with it's own error and cos of the bragg angle I am unsure of whether i need to use partial derivative...
  19. jerromyjon

    Sound wave propagation and doppler shift wrt the medium

    In contemplation and research regarding another thread's question about the asymmetry of doppler shift wrt the medium, I find myself trying to imagine two people talking... or perhaps better yet matching pitch. In still air with both people facing each other at ten paces of course they would...
  20. Essence

    Wave speed dependent on medium not source?

    Homework Statement So in my textbook it says "The speed of the wave depends on properties of the medium, not on the motion of source or observer. An explosion causes pressure variations in the air around it. This "deformation" propagates outward as a sound wave at a speed dependent only on...
  21. A

    Propagation of error: exponents

    Hi all. I have been trying to understand propagation of error of exponents. Most an. Chem textbooks I see say y = a^x, sy/y = (sa/a)*x. But say y = a*b, then sy/y = ((sa/a)^2 + (sb/b)^2)^.5 . if a = b then sy/y= (2*(sa/a)^2)^.5 = 2^.5*abs(sa/a). This shows the rule y=a^x, sy/y= x^.5*abs(sa/a).
  22. J

    Backward-wave propagation in Metamaterials?

    Ok so I am currently doing a research project on reconfigurable polarization sensitive metamaterials. Namely trying to manually control/determine where electrical and magnetic resonance within the structure will occur dependent on geometrical parameters, so it can then be used with some active...
  23. Jesus

    Superluminal propagation of fields

    I am reading about the Velo-Zwanziger problem in which particles with spin higher than 1 propagates faster than light when the particles are coupled with an electromagnetic field. In the original paper: G. Velo and D. Zwanziger, “Propagation And Quantization Of Rarita-Schwinger Waves In An...
  24. fluidistic

    TEM mode propagation between 2 infinite conductor plates

    Homework Statement I am trying to solve a problem from Jackson's book (in chapter 8). I must describe the propagation of a TEM mode through a transmission line that consists of two infinite conductor plates that are parallel to each other and separated by a distance a. There's a dielectric...
  25. F

    Error propagation for a sum of means

    I have a = {a1, a2, .., a1000}, where this set forms a distribution of photoelectrons (pe) seen by a particular photomultiplier tube (pmt) over 1000 repeated events. I then have N sets of these (N pmts), each containing 1000 pe values which I believe are indeed random and independent. So a, b...
  26. fissionary

    Understanding Wave Propagation in a Medium

    I read somewhere that for a wave traveling in a medium a particle (of medium) "gives"(I am not sure if that is the right word) energy to adjacent particle.Is this correct? And if it is why and how does this transfer take place? Also what role does inertia of particle play in wave propagation?
  27. I

    A good introduction on light propagation mode

    Hi, Can anyone explain or point to a good introduction in simple terms the concept of 'light propagation mode'? I am in my final year at high school and need to write a research report on how optical fiber communication systems work. The report needs to include some contents beyond what is...
  28. P

    Error Propagation: Dividing By 20 in Pendulum Timing

    Homework Statement suppose i measure the time t for 20 oscillations fro a pendulum. the period is T. Homework Equations Since T = t / 20 delta T = delta t right? The Attempt at a Solution since the 20 is a numerical value, it does not come in the error propagation, does not? when i used the...
  29. BiGyElLoWhAt

    Carrier particles and E-Field Propagation

    A thought experiment that is a consequense of a question someone asked in my particle physics class: We place an isolated electron. We wait 10 years, and place a half ring of electrons (spaced far apart from each other, but uniform) 10 LY away from our central e. Will our charges move? If so...
  30. 5

    Error Propagation for Tube Volume

    Homework Statement You have a cylindrical tube for which you know the length is 16±0.1 cm and the radius is 8±0.1 cm, what is the error of the volume? Homework Equations The Attempt at a Solution V = π*82*16 = 3216.99 cm But since the r term is squared, must we account for its error twice...
  31. T

    Pressure Propagation through Fluid

    I have been searching for an explanation of how a change in pressure propagates thru a fluid to become isotropic. My question is that if the time scale measured is small enough ( much less than the distance divided speed of sound ) will we see the pressure change have an initial direction and...
  32. S

    Error propagation for non-normal errors

    I have several measurements taken over a time series. Each data point has a standard error value. I need to sum up the data points, and determine the error associated with that sum. The error values across the time series are non-normal, so I'm assuming that I can't use the usual error...
  33. L

    Thought experiment on magnetic field propagation

    Some 30 years ago I learned in the elementary school, that if I move a permanent magnet in a coil which ends are somehow electrically closed, than I need to apply force on the magnet, because the generated current creates a magnetic field which is against the magnet's field. However if the...
  34. L

    How Do You Calculate Signal Propagation Velocity in Transmission Lines?

    Hello, I'm stuck on how to find the propagation velocity of the signal in the Line as stated in Question C on the attached image below. 1. Homework Statement Table one (in the attached image) shows typical values of Z and Y for an overhead line and underground cable. Please note that this is...
  35. J

    Propagation of electromagnetic wave

    will the distance traveled by an em wave depends on temperature,if so then explain
  36. Akash Pardasani

    Propagation of de Broglie waves

    I had a doubt regarding the propagation of de Broglie waves. How do we know the speed of propagation of these waves and also do there characteristics( speed and amplitude and frequency) depend on the source particle ( or they depend only on the motion(momentum) of the source and no whatsoever...
  37. T

    Computation of propagation amplitudes for KG field

    Note: I'm posting this in the Quantum Physics forum since it doesn't really apply to HEP or particle physics (just scalar QFT). Hopefully this is the right forum. In Peskin and Schroeder, one reaches the following equation for the spacetime Klein-Gordon field: $$\phi(x,t)=\int...
  38. X

    FDTD of (ultrasound) wave propagation through muscle

    Im a mechanical engineering student currently, with a third year project of simulating ultrasound propagation through the abdomen. Currently i just want to simulate it going through muscle with no obstacles. I don't really understand where to start, I have formed some equations based on the wave...
  39. N

    Does Time Delay Affect the Curl of an Electric Field?

    I am thinking about the curl of the electric field and want to make sure I have something straight: Say you have a charged particle moving along some prescribed path. The electric field propagates outward at speed c, leading to a "retarded" time that you need to calculate in order to get the...
  40. S

    Radio wave propagation in water

    I'm trying to get my head around radio wave propagation in conductive media such as water, saturated rock, etc. What I know is that propagation is poor but better at lower frequencies and this has something to do with "skin depth". I have read what I can on skin depth but I struggle to relate it...
  41. J

    How to calculate error propagation for several measurements?

    I'm having trouble with error propagation analysis. When you make a single measurement of several variables, say (x,y,z) and you calculate a function f(x,y,z), you just have to apply the common formula of error propagation: $$\sigma_f(x,y,z)=\sqrt{\left| \frac{\partial f}{\partial x} \right|...
  42. D

    Understanding Propagation of DC Current Along a Conductor

    I've been stuck on what I would of thought was a simple/common question but I can't seem to find an answer anywhere. I'm confused as to how a DC current propagates along a conductor (wire) in terms of it's E/H field. I understand that it is these fields that cause the propagation of current...
  43. S

    Error Propagation and Uncertainties in Parameters

    There is a quantity (W) that I would like to calculate that is, ultimately, a function of parameters that I can measure directly (a and b), W = W(a, b) But I cannot measure a and b perfectly, there will be some uncertainty in these measurements. This uncertainty will propagate into my...
  44. T

    Results from TLE & SGP4 propagation - don't seem right & with interpretation

    Greetings all ! I have this problem with SGP4 propagation, that I hope someone can help me out with. I acquired a TLE of the ISS from internet and used the C++ SGP4 propagator to compute future position and velocity vectors of the Station. I am unsure about some aspects of results though and...
  45. T

    C/C++ How to write C++ code using SGP4 to propagate satellite position

    Greetings all ! I really hope this is the right sub-forum for my question, I have chosen it because I've seen TLE being mentioned a couple of times around here. I have done some reading on astrodynamics and orbital mechanics, but I am relatively new to coding. I would like to write some C++...
  46. R

    How is Uncertainty Propagated in Pendulum Period Measurements?

    Hello. I have measured the period of the pendulum T=2.18 +/- 0.02 which is consistent with the true period 2.19865... so I expect myself to find a consistent value of g if I apply the formula propagating the error in the right way. I get g=9.96 +/- 0.2Why?
  47. B

    Scalar propagator for lightlike separation

    Hello everybody. I have a free scalar in two dimensions. I know that its propagator will diverge for lightlike separations, that is t= ±x. I have to find the prefactor for this delta function, and I don't know how to do this. How do I see from, for example, \int \frac{dk}{\sqrt{k^2+m^2}} e^{i k...
  48. V

    What is the Propagation Speed of Gravity Waves in Water?

    Stumbled upon this problem lately. Maybe someone could help me clarify some subtleties I do not see? 1. Consider the propagation speed ##c## of periodic surface of gravity waves with wavelength ##\lambda## and amplitude ##a## in water of depth ##H##. Let ##\rho_{a}## and ##\rho_{w}## be the...
  49. Z

    Propagating uncertainty when calculating acceleration due to gravity?

    Hello, I'm having trouble with a lab report. The experiment conducted was we used an angled air-track and a timer to determine the speed at which an object slid down the track and its acceleration. The final average acceleration we calculated was (61.034 +- 2.227)(cm/s2) We're then given a...
  50. B

    How does the size of an object affect RF propagation?

    Hi there, can anyone please advise how the size of an obstructing object affects the propagation of an RF transmission? Eg, for instance does refraction only occur in objects that are larger than the wavelength or does it occur in objects smaller than the wavelength? I can find heaps of info...
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