Propagation Definition and 457 Threads

Homework Statement 1) I'm using a 4 bit carry lookahead adder to build a 8 bit parallel adder. I'm to calculate the maximum propagation delay time, assuming each gate introduces a unit time of propagation delay. I'm assuming not carry lookahead generators. Would it just be 8 units of...

What must be present for the propagation of a mechanical wave?

Hi! Can some one give me a link where i can find details about finding the velocity of propagation of a mechanical wave in a solid? (i think this wave must be a transverse one)

Hi, I've been trying to reproduce the output of an analytical machine here at work by doing the calculation myself in Excel but I can't get the error to match. Perhaps I am propagating the error incorrectly... The calculation is z = 2^(x-y) The values are: x = 24.96 y = 25.98 and...

Homework Statement how to find the speed and direction of propagation from the wave equation? Homework Equations y(x,t)=Aexp{B(x-ct)^2} The Attempt at a Solution

Say something is a value +/- .05. What happens when you take the inverse of the value? For example, 30 V +/- .05 V. 1/V...what would the error be?

Homework Statement Calculate "f" and its uncertainty, watch the units, show all work. Homework Equations f(x,z)= z/x x=100.5(+ or -) 3.8 cm y=71(+ or -) 1 s The Attempt at a Solution ok so i know that to find uncertainty i have to use the equation delta f(x,y)=df(x,y)/dx...

Homework Statement I was looking through my notes when I saw the following expression of a plane wave represented as a phasor A_{0}e^{i(\vec{k}\cdot\vec{r}-\omega t)} Now I can certainly understand a plane wave propagating along a given coordinate axis say, x or z, and the phasor...

I am concerned about getting the same length to all RAM chips (the output is equidistant to all inputs of the different chips) I heard somewhere that a rule of thumb is that you get .18 nanoseconds of time delay for every inch of tracing. Is this accurate? Is it safe to use this when...

err probably skin too many q's but anyway... what type of waves are made from naturall sources?eg then sun etc...are theren any square waves...im just wandering ifn there's any weirdness or differences when using square waves as a carrier wave in transmitting...if u know any good info sources...

Consider some material object, more or less rigid, with two ends, A and B, like A---B It is at rest at a point in time t_0 in my reference frame. Now I kick it a bit, i.e. I apply some force for a limited amount of time at A in the direction of B. After the kick, the whole object has a...

Homework Statement 2.Explain in your own words what Einstein means by “the principle of relativity”, and why it seems to be incompatible with the theory of electromagnetism (or “the law of propagation of light”). Homework Equations Not an equation but Einsteins answer can be seen here in...

How fast does the magnetic field propagate from a magnetic source? In a vacuum versus through air, etc.? Does the magnetic field propagate faster from a stronger magnet? What is the makeup of a standing magnetic field? Electromagnetic waves or a force field more similar to gravity?

Hi all, I was wondering whether someone can help/guide me. I am doing a project that involves sound propagation in solids. Basically, I have two microphones placed on a surface (say a piece of wood). Then, when a person taps on the surface I can detect the tap and determine the amplitude of tap...

Homework Statement this is regarding propagation of error for a lab i did: we measured the amplitude of a damped harmonic oscillation over a time period, taking amplitude measurements every 1 second for 14 seconds. when graphed (by excel), the plot has the form of y = Ae^(-gt), where A is...

I would like to know how heat would flow in a material being struck by sunlight in vacuum. The usual examples of Fourier heat equation always uses boundaries with fixed temperature or under convection. How do I calculate this when the surface is absorbing and emitting radiation according to...

In the beginning of their book, Peskin & Shroeder say that replacing non-relativistic energy p^2/(2m) with the relativistic one \sqrt{p^2 c^2 + (mc^2)^2} does not remove infinite propagation speeds given by the propagator \int\frac{d^3p}{(2\pi\hbar)^3} e^{-i(E_p t - p\cdot(x-y))/\hbar} Does...

Ok, this isn't a homework question -- more out of curiosity. But it seems so trivial that I hate to post it under "General Physics" We all know the standard formula for error propagation: \sigma_f = \sqrt{\dfrac{\partial f}{\partial x}^2 \sigma_x^2 + \dfrac{\partial f}{\partial y}^2 \sigma_y^2...

Hi, I wasn't really sure whether to put this post under Physics or Engineering. I was just wondering whether someone can gimme some help or info or guidance... I am currently working on a project in which I am using the FFT (Fast Fourier transform) algorithm. In a nutshell, I am trying to use...

Suppose we have a stretched string, with one of its end fixed at a wall. Now if we just jerk the string(up and down), we get a mechanical wave, i.e. the disturbance caused by us at one end of the string travels to the other end. Now the question is, how and why does the disturbance travel...

Hello, I'm familiar with the common calculus approach with partial derivatives to evaluate error propagation in calculations with random variables. However, I'm looking for a way to derive the classic formula with the sum of fractional errors squared: {\left(\frac{\Delta Z}{Z}\right)}^2 =...

Please consider a plane wave that propagates through a dielectric with friendly properties (isotropic, non-conducting...) with speed c/n. What would happen if we remove the dielectric and the wave continues to propagate in empty space?

I want to know how to treat propagation of errors in general. When the transformation of variables is a transformation of $R^n$ to $R^n$ it simply involves a jacobian: g(\vec{y}) = f(x(\vec{y}))|J| With J_{ij} = \frac{\partial x_i}{\partial y_j} (see...

hi! Can anyone explain how an electric field propagates from one point to another? For example if i touch two 6ft wires to the ends of a 5V battery, i'll get 5V across the end of the wires after a propagation delay. How does the electric field (voltage) of the battery make it's way down to...

Homework Statement I can't seem to find online how to calculate the error propogated by trigonometric functions. That is, I know the uncertainty in \theta but am not sure how to deal with it when I apply the tan function. I am quite okay with how to deal with all the basic...

Hello, I am currently using a 555 timer to check the period of a square wave input: The timer is triggered off the leading edge of the first square pulse, and if a second leading edge is detected OR the 555 becomes untriggered then a clock signal will be sent to a D flip flop and its state...

When does the wavefunction propagate at a finite speed, and when instantaneously?

Hi, all, My question is if I have two plane E&M wave traveling in the x-z plane, and they are polarized along the y direction, and I know that there is an angle theta between their propagation vectors, how do I set up the equations to get the intereference pattern in the z direction? I...

Consider a wave packet represented by \Psi (x,t) = \int_{k-\Delta k}^{k+\Delta k} A \cos\left[k'(x-ct)\right] dk' A constant and ck' is the dispersion relation SOlve th integral and describe teh propogation properties of this wave packet. Assume this means that the phase and group...

We recently did a Resistance in Circuits lab. My coded resistances were 33, 100 and 220. The measured resistance was 33.3, 101.6 and 219 So we did 3 setups. (Series, Parallel and Combination) Series = 351.8 measured ohms Parallel = 22.5 measured ohms Combinations = 101.5 measured...

I hope this is the right place for this... Well, I have a lab where we measured the charge/mass ratio of an electron using a helmholtz coil and vacuum tube. I need to calculate the propagation of uncertainty in my final value. The formula for calculating the e/m ratio is the following...

Hi! If anyone could help me with this problem I'd be deeply appreciative: Speed of Propagation vs. Particle Speed. The equation y(x,t)=A cos2(pi)f (x/v - t) may be written as y(x,t)= A cos[(2(pi)/lamda)(x-vt)] a) Use the last expression for y(x,t) to find an expression for the transverse...

Lets say you got a glass cube and a small light source embedded at the exact center of the glass cube. Now if you want to paint a circle on each face of the cube so that the light is prevented from leaving the cube, what is the minimum radius of the circle that you need to paint? Let say...

regarding plane waves theory and their properties, for lossy media (conductors) in different books appear a formula that represent alfa y beta constants in the followig way: alfa = beta = root square( pi*frequency*mu*sigma) valid for good conductors (high loss material) I have checked...

Problem: The equation of a certain traveling transverse wave is y(x,t)=4.00sin(81.0(pi)t - 1.590(pi)x) where t is in seconds and x and y are in cenimeters. Find the speed of propagation, the period and the wavelength for these waves (express you answer in units of m/s) So, I know A...

Hi All, Here is my question regarding the solution of this little movie => http://www.somasimple.com/flash_anims/ap_003.swf A thin elastic tube (thickness = 1) is connected with a thicker one (40 times thicker than the previous section). The tubes are poured with water. A wave is is traveling...

Do you aggree that there is an inertial reference frame in which light in free space propagates isotropically whereas in all other inertial reference frames its propagation is anisotropic?

charge and its "propagation" if we imagine a charge. Now other "charges" can sense the presence of this charge when they are sufficiently close. This is due to temporary photons? Could some explain in a simple manner how this works? Take electric charges for instance.

This might be a stupid question but, taking a shower yesterday, I was wondering how is light propagating through the air molecules. For example, take the light coming from a distant star entering our atmosphere. Between my eyes and the star there are billions of air molecules. How do the photons...

I am verifying and validating a rotational state propagator used in a dynamic simulation package. I have found some problems and solutions to them. This post outlines the propagation, the problems, and the solutions. Some questions before I start: - Has anyone else analyzed stability and...

confused! how do you calculate propagation delay of circuit and paths? Hello everyone, this book explains literally nothing about propgatation delay and how to calculate propagation delay of gates and the paths. And yet one of the questions says...

I know there is a formulas for doing error propagation with separate formulas for when dealing with powers, multiplying/dividing, and adding/subtraction. What about if I have the formula F=4*pi^2*r*m / T^2...? Also should i do error propagation for the varibles in the formula r (radius), and...

Hi, I'm trying to get my head around electric field propagation in an electric circuit. If you have a battery with no circuit I imagine the electric field between the terminals would look like the magnetic field lines between the two poles of a magnet. What I can't visualize is what the field...

Hi! I was wondering if you can give me some adivice on how to approach this problem: In a physics lab, light with a wavelength of 560 nm travels in air from a laser to a photocell in a time of 16.5 ns. When a slab of glass with a thickness of 0.860 m is placed in the light beam, with the...

probably easy question a sinusoidal wave is propagating along a string in the +x direction. 10 waves pass by a point every 10 microseconds. the wave exhibits the following characteristics: a) at t=0 and x=0 , the wave propagation speed is 30 m/s, and the Oscillation speed is 2.5 mm/s in...

I was collecting data for a simple physics lab today when I stumbled upon a question I couldn't answer. Very basically, the lab consisted of measuring the time it takes a ball to drop a variety of distances, between 0 and 100cm. By plotting \frac{y}{t} vs. t (where y is height and t is...

I am utterly confused with this problem, I am not quite sure how to formulate an equation to solve for the answer : The speed of sound in steel is about 4.2 kilometers per second. A steel rail is struck with a hammer, and there is an observer some distance away with one ear to the rail. The...

Imagine a massless, classically zero curvature, infinite spacetime in which propagates a single actual photon. What eventually motivated this photon to propagate, and does its trajectory or energy vary due to the spacetime vacuum energy?

propagation of errors? (lab "phenomenon" question) In our lab, we are measuring the acceleration due to gravity. We do this by dropping an object through a photogate, which records position vs. time data as the object falls. From this position vs. time data, the computer uses derivatives to...

Well, this is my question. It's something like a philosophical thinking. Look at this problem of the Heat Equation: \frac{\partial T}{\partial t}=\alpha \frac{\partial^2 T}{\partial x^2} with: 0<x<L T(x,0)=g(x) and T(0,t)=T_1 T(L,t)=T_o This is a parabolical PDE...