Amplitude Definition and 825 Threads

I found via this forum the hint to use the inverse squared equation to differentiate to find the resonance frequency from the amplitude equation (equilibrium not transient solution). Thank you! (AlephZero?) When substituting the resulting frequency for the resonance into the amplitude...

Homework Statement The sound level in decibels is typically expressed as β = 10 log(I/I0), but since sound is a pressure wave, the sound level can be expressed in terms of a pressure difference. Intensity depends on the amplitude squared, so the expression is β = 20 log(P/P0), where P0 is the...

Does the amplitude of a wave changes when the source is moving? I am mainly interested in waves in a medium (e.g. sound, water...) No text about Doppler effect I have found mentions anything about the amplitude so I guess it does not change. However in the case if the speed of the source...

Might be a naive question. In many places, specially in the Hubbard model, people use a minus sign before the tight-binding hopping amplitude. What does the negative sign signify for? Any special intention? Thanks.

Homework Statement 1) The position operator x has a continuous spectrum of engenvalues {x'} with corresponding eigenkets {|x'>}. Expand this state in terms of the position eigenstates. 2) Suppose the transition amplitudes c_a',b' = <a'|b'> are known where {|b'>} are the eigenstates of a...

Homework Statement A wave with the amplitude 4 cm travels along a rope that is fixed to a wall. The wave reflects from the wall. What is the amplitude of the reflected wave? Homework Equations I know it's something with light, could you explian in more detail? The Attempt at a Solution

if you have the equation: x(t) = Acos(ωt + ϕ) and you have the following information: A 200 g block hangs from a spring with spring constant 10 N/m. At t = 0s the block is 20 cm below the equilibrium position and moving upward with a speed of 100 cm/s. The answers give a short method of...

Hi What is a probability amplitude - I have read the article on wikipedia and I still don't get it. Hope someone out there can explain it to me.. Thanks

I have got an assignment in which i need to compare wave interference, so i am going to use decibels readings which i had gotten from experiments and the reference amplitude which is 60 to calculate this very very confusing task. i have gotten these formulas derived from which i derived...

If I modulate a pulse X(t) with a.) a sine wave or b.) a cosine wave, I have the frequency spectrum expressions a.) \frac{1}{2j}[X(f-f_0)-X(f+f_0)] b.) \frac{1}{2}[X(f-f_0)+X(f+f_0)] When I plot these for a pulse, I see a difference in the magnitude spectrum, but I should not expect...

Any wave is identified by its wavelength (or frequency), and the wavelength is the distance between the two consecutive crests (or troughs) in wave trains. But wave is not identified by its amplitude. The wave could have been described by the amplitude as it doesn't require two wave trains (or...

Homework Statement A simple pendulum consists of a spherical bob of mass 0.052 kg and diameter 1.1 cm attached to a thread of length 920 mm. b) The bob is released at rest with the thread taut at an angle of 5 degrees to the vertical. Calculate: i) the amplitude of the oscillation...

Aight, so I have this problem where I think about something and then I understand it, but then instead of stopping thinking and understanding it, I keep thinking and stop understanding it. Unfortunately then my poor brain is so confruzed that I am unable to backtrack to understanding, and I...

Is amplitude always perpendicular to the rest axis? in a wavelength amplitude it the distance between either the crest or through from the equbilium line. then in the case of transverse vibration, what is its amplitude? thanks

Griffiths p406 it talks about Guided waves http://img593.imageshack.us/i/imageyyf.jpg/ please see this photo... Hmm...Why are both of "E0、B0 independent of z? Is it about the fact that it propagate down the tube along z axis?

hello, if I have a sinusoidal signal that has changing amplitude and phase with respect to time, how can I find the amplitude and phase with respect to time? So given x(t) the probem is to find a(t) and p(t)? Thanks.

Homework Statement The horizontal end points of the swing pendulum are 10 cm apart. What is the amplitude of the pendulum. Homework Equations v=f(lamda) The Attempt at a Solution

Is there any statement which perfectly captures what the probability amplitude, in the many worlds interpretation, represents? To say that there is an x chance of y happening is non-sensical because, according to the interpretation, y WILL happen in at least one universe. To say that there is...

Homework Statement Two sinusoidal waves have the same angular frequency, the same amplitude ym, and travel in the same direction in the same medium. If they differ in phase by 50 degrees, the amplitude of the resultant wave is? Homework Equations The Attempt at a Solution How do...

Hello, :smile: I did an experiment on full wave rectification using center tap transformer. The transformer read: Input 220V, Output 12V, 12V. I used two diodes and 1 micro farad capacitor. As you see capacitor's capacitance is very little so it didn't effect the overall output because I...

Homework Statement What value must be equal for two different masses to oscillate with the same amplitude? Homework Equations x(t)= Acos(wt+p) v(t)= -Awsin(wt+p) The Attempt at a Solution The answer is (xo)^2+(w*vo)^2 But I really don't understand why... does it have something...

Ok so I was sitting out back one day listening to some music with some friends around. We had some music playing on a stereo inside the house and we were out the back with the glass door open about 10 cm's. I thought I noticed that some sounds with different frequencies seemed louder then...

Homework Statement Say that the logarithmic intensity of a dolphin's sound is 50dB as measured as 1m away. What would be the ampltude of the pressure wave at 20m from the dolphin? My Question/Problem: How are you supposed to factor in the 20m away? Homework Equations Po=...

Expansion of spacetime stretches wavelengths and produces the red shift. Does it also stretch the amplitude of the wave, and make distant stars look brighter and therefor nearer?

The expansion of spacetime stretches and red shifts the wavelength of light. Is the amplitude of the wave stretched as well? So that very distant stars appear brighter, and therefor nearer?

Homework Statement Not really a homework question, but related none the less. I'm confused about what exactly the amplitude spectrum is. As well as the power spectrum. Homework Equations Not really taking a purely mathematical approach here, I'm using numpy for python. Specifically the fft...

In most books the amplitude does not change when water waves pass from deep to shallow water. In some books the diagrams show an increased amplitude. Which one is correct?

While reading about frequency modulation, I found that it was clearly written that the amplitude of the carrier wave remains unchanged. However, i didn't find a statement stating that the frequency of the carrier wave remains unchanged for amplitude modulation. So, is the frequency of the...

1.A block of mass M=1 kg rests on a frictionless surface and is connected to a horizontal spring of force constant k=25 N/m. The other end of the spring is attached to a wall. A second block of mass m=500 g, rests on top of the first block. The coefficient of static friction between the blocks...

URGENT: precalc project amplitude help! Homework Statement I am doing a project for my precalc class which explores the applications of sine waves in real life. I chose to do bat and dolphin echolocation. so far the information i have found online has given me frequency in Hz, length of each...

I have a process that a scalar and a photon at the final state. When we take the complex conjugate and sum over photon final polarization state...it give negative sign in the differential cross section...what does this mean? the trace didn't give negative value. M=M^{\mu}\cdot\epsilon_{\nu}...

What is the relationship between harmonics and wave amplitude in a resonant object? Lets say we have an object which has a natural resonant frequency of 50hz. we connect that object to a signal generator set at 50hz and note the amplitude of the oscillations the object. Next we go up one...

Is it possible to have an infinite value for the amplitude of a Fourier coefficient? The signal is sin(w0t) from 0 to T/2. My resulting coefficient formula was Fn = 2/[4pi(1-n)] + 2/[4pi(1+n)] so for F1 i got infinity ... is this possible? or is coefficient just wrong?

Hi everyone, plx help me on this! I've worked out frequency modulation but can't understand amplitude modulation ... A sinusoidal carrier wave has a frequency of 750kHz and an unmodulated amplitude of 4.0V. The carrier wave is to be amplitude-modulated by a sinusoidal signal of frequency...

Homework Statement a 185g mass attached to a horizontal spring oscilates at 5.2Hz. At t=0s, the amss is at x=5.80 and has a vx=-40.0cm. determine the amplitude Homework Equations The Attempt at a Solution

Homework Statement 1. When a wave is reflected from a mirror, there is no change in its a) Amplitude b) Frequency c) Velocity d) All Homework Equations The Attempt at a Solution I think frequency changes,not sure

Homework Statement a .25kg block oscillates on the end of a spring with a spring constant of 200N/m. If the oscillation is started by elongating spring to 0.15m and giving the block a speed of 3.0m/s. The amplitude is? Homework Equations omega= sqrt(k/m), Vm = (omega)Xm The Attempt...

Homework Statement In a typical household current, the electrons in the wire may have a drift speed of 1.3×10−4 m/s. Actual household current is not a direct current, but instead is an alternating (oscillating) current. (If you have ever received an electric shock from an outlet, you have...

Suppose one pendulum consists of a 1-meter string with a bob that is an aluminum sphere 2 inches in diameter. A second pendulum consists of a 1-meter string with a bob that is a brass sphere 2 inches in diameter. The two pedulums are set into oscillation at the same time and with the same...

I have a spreadsheet of Accelerometer data out of an iPhone and I have calculated the displacement in the three axis. I would like to figure out how to take this info and calculate the frequency, avg. amplitude, and the highest amplitude. Excel has a frequency function but I would like to...

Homework Statement The displacement function for a string carrying a transverse wave is y(x, t) = 2.0mm*sin(20*x/m − 600*t/s) Determine the amplitude, frequency, velocity and wavelength of the wave. Determine the maximum transverse speed of any point on the string. Homework...

Homework Statement So I have to make a snapshot & history graph of a wave. I chose to do a radio wave. However, I just want to know what the measurements for amplitude and wavelength. Also, there's no specific way to draw a snapshot of a radio wave is there? I can just draw the wave...

Basic premise: a pure tone sine wave can be modeled with a pendulum and the rate of amplitude decay can be manipulated with a friction coefficient. So... does anyone know how this is actually done? In other words if you picked a pure tone (let's say middle C @ 261.6 Hz) initiated at a certain...

I've two electromagnetic waves (light) with amplitudes 1x (normal) and 2x (double) amplitude. And I want to pass these two waves through a "normalizer" expecting 1x amplitude for both waves. Question is: Is such a "normalizer" possible and/or exists. I'm not looking for any electronic...

hey do you know how to calculate what is the physical size of the amplitude of a radio wave? like I know how to calculate the wavelength but to draw a scale physical representation of that wave in space, how do I use amplitude to calculate the (y axis) height of the peak periods?

mass attached to spring on horizontal frictionless surface. given: position x at time zero, velocity at time zero (not equal to zero), spring constant, and mass. how do I figure out the amplitude?

In quantum optics, I've been looking at how one can show electromagnetic field is equivalent to a harmonic oscillator. They give the E field as, in one dimension: E_x (x,t) = A . cos(wt) . sin(kz) where the symbols have their usual meanings. A is given as SQRT[2w^2 / Ve]...

Does anyone know a simple derivation that explains why the energy of a wave is proportional to the amplitude squared?

Hello, So I was studying for my exam and came across this exercice we did in class and which I really don't know how we got the answer. It says that if we have a FM with a carrier frequency of 4MHz, and the bandwidth is 400KHz, what is then the maximum deviation.. The answer is 200KHz...

Homework Statement Im confused about what exactly is the period and amplitude of a spring... Is the period -during ocillation-from top to bottom back to top? or vice versa. and is the amplitude 1/4 of the period? Homework Equations The Attempt at a Solution