What is Amplitude: Definition and 866 Discussions

The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). There are various definitions of amplitude (see below), which are all functions of the magnitude of the differences between the variable's extreme values. In older texts, the phase of a period function is sometimes called the amplitude.

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  1. moe darklight

    Questions about electromagnnetic wave: amplitude

    I'm having a little trouble understanding some of this. Here's a few things I don't understand: - are wave amplitude and frequency/wavelength correlated, or are they independent of each other? (I understand freq and length are correlated because the speed of light is constant) ... (my guess is...
  2. K

    What is the electric field amplitude 2m from the source

    Homework Statement A 60 W monochromatic point source is radiating equally in all diresctions in a vacum. What is the electric field amplitude 2m from the source. Homework Equations Intensity=Power/(4*Pi*r^2), Intensity proportional to square Amplitude The Attempt at a Solution...
  3. B

    Ratio of Resultant Wave to Common Amplitude: Pi/2 Rad Out of Phase

    Two identical traveling waves, moving in the same direction, are out of phase by Pi/2 rad. (a) What is the ratio of the amplitude of the resultant wave to that of the common amplitude of the waves I'm having trouble with this problem because I feel like I'm not given enough information...
  4. O

    Does Amplitude Affect Period?

    Here is a quick question, and it would be nice if you someone could answer yes or no. I need it to do a problem because I am unsure whether it is. The question is: Does amplitude affect the period of oscillation of a spring in simple harmonic motion? I think no because of the equation: T =...
  5. C

    Maximum oscillation amplitude for block

    Problem: A 1.0 kg mass is riding on top of a 5.0 kg mass as it oscillates on a frictionless surface. The spring constant is 50 N/m and the coefficient of static friction between the two blocks is 0.50. What is the maximum oscillation amplitude for which the upper block does not slip...
  6. N

    What will be the amplitude and frequency of vibration

    A fisherman’s scale stretches 2.8 cm when a 3.7 kg fish hangs from it. a. What is the spring constant, and b. What will be the amplitude and frequency of vibration of the fish is pulled down 2.5 cm more and released so that it vibrates up and down? a) F=ma F=(3.7 kg)(...
  7. N

    How Do You Calculate Current Amplitude in a Parallel RC Circuit?

    A resistor with a resistance of 500 ohms and a capacitor with with a capacitance of 2 x 10^-6 f are connected in parrallel to an ac generator that supplies an rms voltage of 260 v at an angular frequency of 377 rad /s find the current amplitude in the resistor (Ir)peak. I know I have to...
  8. A

    Calculating RF Range & Amplitude from Spark Gaps

    How does one calculuate/analyz RF range and amplitudes given off buy discharging spark gap.
  9. A

    Amplitude for a particle in state

    <-z|x> is the amplitude for a particle in state |x> to be in state |-z>. a particle in state |x> can be in |+x> or |-x>, correct? |+x> = [1/sqrt(2)]|+z> + [1/sqrt(2)]|-z> |-x> = [1/sqrt(2)]|+z> - [1/sqrt(2)]|-z> How would this be calculated? Would the amplitude be: <-z|+x>...
  10. Z

    Question about Inverse SQRT of Amplitude

    Before we begin, recall the simple formulas; for reference see http://eosweb.larc.nasa.gov/EDDOCS/wavelength.html Velocity / Wave Length = Frequency (Hertz) Speed of the wave = Frequency x Wavelength Wavelength = Speed of the wave / Frequency AND Where TIME is the RECIPROCAL of...
  11. O

    Dual Side Band Amplitude Modulation Quick Question

    Hi, a quick and easy one I hope someone can help me with. What would be the general expression for a DSB-AM modulated signal in terms of the Carrier Signal C(t), Baseband Signal S(t) and the modulation index m? Many Thanks
  12. T

    Platform on Springs, how to find amplitude?

    I have been working on this problem for an hour and can't seem to figure it out. I know there must be something fundamental that I must be doing wrong. Can someone give me a pointer? A platform of mass 0.8 kg is supported on four springs. A chunk of modeling clay of mass 0.6 kg is held...
  13. F

    Dimensions of a probability amplitude (matrix element)?

    Greetings. I'm a little bit confused about the dimensions of a probability amplitude in a QFT calculation. My understanding a the squared, spin averaged\summed Feynman diagram should be dimensionless. However, if we consider a decay process, say pair creation from a photon or the decay of the...
  14. Amith2006

    Change in amplitude of wave on reflection

    Sir, When a wave is reflected from a free end or a rigid end, will there be a change in amplitude always?
  15. P

    Probability and Wave Amplitude: The Born Rule

    In 1926, Born suggested that the square of the wave at any point is proportional to the probability of finding the particle at that point. Born was led to this interpretation by relationship between the intensity of light and the square of its amplitude. Since we can renormalise the function...
  16. S

    Understanding Particle Poles in Amplitude Expressions: Explained

    Gents I have one question: If I have expresion for amplitude of some process and this amplitude has pole, I say I have particle caryring such features (suppose mass that makes this pole), if I change some parameters in expression for amplitude and if I get another pole, I say in this case...
  17. U

    Amplitude of multislit grating

    The formula for the amplitude for a multislit grating is: A(Y,t)=\frac{M}{R}cos \left(\frac{2 \pi R}{\lambda}-2 \pi f t \right) \frac{sin^2 \left[(2N+1) \frac{x}{2}\right]}{sin^2 \left[\frac{x}{2}\right]} a spectra would look something like...
  18. N

    How do you find the amplitude?

    a block of mass 4kg is hung from a spring, causing it to stretch 8cm at equilibrium. the 4kg block is then replaced by a 5kg block. the accleration of gravity is 9.8m/s^2. how far will the 5kg block fall before its direction is reversed? i don't know if this helps but i found K for the...
  19. M

    Initial Amplitude and the Release Point

    Question: "A pendulum with a length of 2.82m is released from an initial angle of 17.5 degrees. After 1100s, its amplitude has been reduced by friction to 5.30 degrees. What is the value of b/2m?" Word Done: A = A(initial)e^(-betaT) Basically I have done the problem on the basis...
  20. T

    Calculating Amplitude of Elliptically Polarized EM Wave

    Suppose I have an eliptically polarizied EM wave, whose electric field can be written as \vec{E}=A\cos(kz-\omega t)\vec{e}_x+B\sin(kz-\omega t)\vec{e}_y, where the constants A and B are amplitudes of the x and y components of the beam, respectively. How would I report the amplitude of the...
  21. D

    Spring, Amplitude and Acceleration

    Ok, I'm stuck again... A block of mass M1=0.490 kg sits on a block with a mass of M2=4.50 kg that rests on a frictionless surface and is connected to a spring. The spring has a spring constant of k=16.6 N/m. The block is displaced and undergoes Simple Harmonic Motion. What is the largest...
  22. S

    Are Electromagnetic Waves Constantly Changing in Amplitude?

    argh hello guys, I've been trying to find out a simple answer to this question but all the resources I've looked at seem to skim over it or contradict each other, but simply: Do electromagnetic waves have a variable amplitude? "Intensity" is not necisarilly the same, if you're using the...
  23. 2

    How Do Amplitude and Frequency Affect the Speed of a Spring in a Wave?

    Is the speed of a spring in a wave affected by changes in amplitude? If yes, describe. Is the speed of a spring in a wave affected by changes in frequency? If yes, describe.
  24. T

    Power and Amplitude of sound wave

    For my homework, To find Amplitude of the wave, for a longitudinal wave traveling down a copper rod. Given: frequency, radius of copper rod, average power, Young's constant, density, wavelength. what equation should I consider? I'm thinking something like P=(omega*amplitud)^2 because I...
  25. F

    Find amplitude of a membrane

    hi, this is the last question I'm having trouble with.. the question is: Fine sand is sprinkled on the horizontal membrane, which vibrates in the vertical direction with frequency f = 500 Hz. The sand particulates bounce at the height of 3 mm over the level of the position of equilibrium of...
  26. P

    Calculate Amplitude of EMF Induced by Radio Station

    Sry, i think i put this in the wrong forum last time. Here is the problem i have been working on. An AM radio station broadcasts isotropically (equally in all directions) with an average power of 3.20 kW. A dipole receiving antenna 70.0 cm long is at a location 4.00 miles from the...
  27. G

    Propogation Amplitude of Free Particles from \vec{x}_0 to \vec{x}

    Consider the amplitude for a free particle to propogate from \vec{x}_0 to \vec{x}: U(t) = \left\langle \vec{x} | e^{-i H t} | \vec{x}_0 \right\rangle I guess I don't understand what it means for a particle to propogate from one "position" to the next. If the particle is not in a...
  28. O

    Amplitude of an oscillating system graph

    Recently, there was a question i came across that asked: The graph shows how the amplitude of an oscillating system varies with its driving frequency. What will the resultant graph be if the system is placed in a fluid? My answer was that the peak would be smaller and shift to the right...
  29. H

    Calculate Wave Amplitude for T, u, lambda, g: A Step-by-Step Guide

    A large ant is standing on the middle of a circus tightrope that is stretched with (T) tension . The rope has mass per unit length (u). Wanting to shake the ant off the rope, a tightrope walker moves her foot up and down near the end of the tightrope, generating a sinusoidal transverse wave of...
  30. Y

    Expression of AM Cosine Wave using Phasors

    An AM cosine wave is represented by x(t)=12+7*sin(pi*t-(1/3)*pi)]*cos(13*pi*t). Use phasors to show that x(t) can be expressed in form of: A1cos(w1*t+phi1) + A2cos(w2*t+phi2)+A3cos(w3*t+phi3) where w1<w2<w3. I am really stuck with this. don't know where to start. can someone please help me...
  31. J

    The relationship between dynamic stiffness and vibratin amplitude

    many references tell that the dynamic stiffness will reduce when vibration amplitude increases. And the experimental result is just so. But why there is such rule?who can explain it theoretically?
  32. quantumdude

    Amplitude Modulation with Function Generators

    Hello everybody, I am trying to use a pair of Tektronix FG 503 Function Generators to modulate a carrier wave and produce an AM modulated signal. I tried running the output of one generator into the VCF input of the other, but it seems to give me FM modulation. I did this because I am...
  33. B

    Trouble understanding how charge density is the amplitude squared

    A little while ago I posted a thread asking the same question but didn't really get an answer so I am going to try to rewrite it. I'm having trouble understanding how the charge density of an electron (or any particle) is the square of its wave function. One problem I have is when there are...
  34. M

    What is the difference in amplitude between red and blue photons?

    What is the difference in amplitude between red and blue photons? Which has a great amplitude? Where is the definition of a photon's amplitude defined?
  35. C

    Vibration Amplitude: Structure Withstands # of Cycles w/ X,Y

    A structure withstands a vibration of amplitude x and frequency y for z number of cycles. How many number of cycles the structure will withstand if the vibration amplitude is doubled. How many number of cycles the structure will withstand if the vibration frequency is doubled?
  36. T

    What is the Amplitude and Wavelength of a Real Wave in Nature?

    I am interest in finding the amplitude and wavelength of an actual wave in nature that apply to the equation: wavelength = v/f where v = speed of light. This kind of wave would be example of light wave, electron wave, or radio wave, I assume. What I need is the exact measurement of it's...
  37. U

    Calculating Amplitude of Oscillation for Colliding Objects on a Spring

    For lunch you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.300 kg of Italian ham. The slices of ham are weighed on a plate of mass 0.400 kg placed atop a vertical spring of negligible mass and force constant of 200 N/m. The slices of ham are...
  38. W

    Calculating Oscillation Amplitude & Period of Deli Plate

    Hi I'm attempting this question and I'm wondering if this is the correct way of going about it or if I'm completely off track: For lunch you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.300 kg of Italian ham. The slices of ham are weighed on...
  39. A

    Maximum Velocity When Doubling Amplitude & Period of SHM

    what happens to the maximum velocity if you double both Amplitude and period of a SHM? the equation is x(t) = A cos (wt + f) v(t) = -A w sin (wt + f) f is phase constant, w = angular velocity i know if i double A and T, the first part of the v(t) equation will be like: -2A *...
  40. P

    Tsunami amplitude change question

    When a tsunami comes from a deeper region into a shallower region, its amplitude changes?Would you figure out a equation related to the content of energy of a wave in terms of frequency and amplitude? How can I get a brighter pattern of diffraction of a water wave besides adjusting the hole...
  41. M

    Antenna Amplitude: Factors Affecting Wave Size

    What affects the size of the amplitude of a wave sent by an antenna?
  42. D

    Light Wave Amplitude: Variation & Length Explained

    Maybe this should be under QM but it's a pretty simple question. How does the amplitude of a light wave varie (if it varies at all), if it doesn't what is the lenght?
  43. D

    Quardrature Amplitude Modulation

    Quardrature Amplitude Modulation. I know the basic techniques, like when you have 1 point and only two signals are to be multiplexed. But the constellations got me a bit confused. My text-book doesn't explain it thoroughly, and there isn't much deep information about it on the internet...
  44. C

    What Speed Ensures Maximum Amplitude for a Mass on a Spring System?

    box of mass 2kg on spring with k=13 N/m, they are on a wheel. The road has an amplitude δ = 2 cm as shown above. What speed is necessary for the mass to have a maximum amplitude x = 2δ . the picture looks something like this __ |__| m=2kg \ / k=13 N/m \...
  45. P

    Period of Simple Harmonic Motion: Amplitude Independence

    Why is the formula for period of simple harmonic motion independent of amplitude?
  46. F

    Find the spring constant and the amplitude of the simple harmonic moti

    Having a little trouble with this one: A 4kg mass is attached to a spring and executes simple harmonic oscillation with a period of 1.50s. The total mechanical engery of the system is 12J. What is the spring constant. Determine the amplite. I was able to find the amplitude which is 0.585m...
  47. M

    Wave pulse - find amplitude

    Hey dearest people Who can help me solve the following problem? A wave pulse is described by, y = 0.04exp(-0.6(68x - 7600t)2) [m]. Here t is measured in seconds, x and y are measured in meters. a) What is the velocity of this wave pulse? Be careful to get the sign of the velocity...
  48. M

    Solving for Amplitude of a Brick on a Piston with SHM: Help Needed!

    I have no idea why I can not get this question, but here it is: A brick is resting atop a piston that is moving vertically with simple harmonic motion of period 1.19 s. At what amplitude will the brick separate from the piston? I know that once the acceleration is greater than that of...
  49. H

    Wave Amplitude and Knot Movement

    A 4.0 Hz wave with an amplitude of 12 cm and a wavelength of 30.0 cm travels along a stretched string. (a) How far does the wave travel in a time interval of 3.0 s? m (b) How far does a knot on the string travel in the same time interval? m I got the answer to part (a) by using...
  50. N

    Calculating Amplitude of Brick Separation from Piston with SHM

    A brick is resting atop a piston that is moving vertically with simple harmonic motion of period 1.08 s. At what amplitude will the brick separate from the piston? I came across this question reviewing for my test next Thursday. Anyway, I can calculate the angular frequency using the...
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