resonance Definition and Topics - 91 Discussions

Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies.Frequencies at which the response amplitude is a relative maximum are also known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy.
Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance (NMR), electron spin resonance (ESR) and resonance of quantum wave functions. Resonant systems can be used to generate vibrations of a specific frequency (e.g., musical instruments), or pick out specific frequencies from a complex vibration containing many frequencies (e.g., filters).
The term resonance (from Latin resonantia, 'echo', from resonare, 'resound') originated from the field of acoustics, particularly the sympathetic resonance observed in musical instruments, e.g., when one string starts to vibrate and produce sound after a different one is struck.

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  1. K

    I Help Designing a Resonance Box for Tuning Forks

    I got these tuning forks from someone. However, I do not have the resonant box for amplification of the sound. I decided to get it made so that I can experience the fundamental frequency (and other harmonics) more clearly. I am planning to provide this design. In summary, the box would be...
  2. Huzaifa

    Molecules with an extended π system well described by resonance hybrid

    Homework Statement:: [...] Molecules with an extended π system such as linear polyenes and polyaromatic compounds are well described by resonance hybrids as well as by delocalized orbitals in molecular orbital theory. Relevant Equations:: N/A This is not a Homework question. I was reading...
  3. T

    Engineering Resonance in AC circuits

    Here's my attempt at a solution.
  4. cianfa72

    Question about the energy stored in an RLC parallel resonant network

    Hi, I've a doubt about how to the energy is stored in a 'real' RLC parallel resonant network feeds from a sinusoidal source. Take a 'real' RLC parallel network having a resistor ##R_s## in series with the inductor ##L_s## (modeling its loss) with the capacitor C in parallel and consider it in...
  5. S

    Chemistry Drawing resonance structure for this O-CH2 ion

    ion shown: My answer: the following is the answer of the question: I identified the major contributor correctly, but the resonance structures, but the second resonance I drew is missing in the answer sheet. Can anyone tell me why the second resonance structure is not part of the answer...
  6. S

    Chemistry Drawing resonance structure for SO42

    I was told that there are six resonance structures for SO42-, as shown below. I am wondering why this structure with single bonds is not one of the possible resonance. I understand that it is unfavorable as the formal charges are spread out over all four atoms, but shouldn't is still be a...
  7. A

    Finding the resonant frequency of this "discriminator" demod circuit.

    This is the FM demodulation "discriminator" circuit. It is one of the simplest analog demod setups one could think of. An RF (FM) voltage signal is applied at V12 and the voltage at ' a' ' is supposed to contain the AF signal in its amplitude. The idea behind the circuit is that it resonates at...
  8. lola1227

    Beats and Resonance - How to Find the Length With only Frequency?

    So, my thinking was that we use the formula V=f(lambda) and substitute the f so, V = 440(lambda) but then i dont have another number to cancel or rearrange by. And since closed air columns have the fractions of 1/4, 3/4, and 1 1/4 (5/4), we could divide by those?
  9. J

    Coupling of resonant modes in a 1D Photonic Crystal

    In 1D Photonic crystals, a defect can be introduced to create a defect/resonance mode and enable transmission. At first considerations, the thickness of the single defect layer determines the transmission frequency. Moreover, if it is a half-wavelength layer it will enable a resonance condition...
  10. T

    Resonance vs. Conservation of Energy

    I can solve the equation for a damped oscillator with a forcing function. I can then plot the Kinetic and Potential Energy. They will be out of phase, of course (KE peaking when PE is zero, and vice versa) And we know that when the input frequency is close to the natural frequency, the system...
  11. Nathan M

    Understanding frequency calculations of an object (e.g human body)

    Apologies for the noob question. The frequency of the human body can be calculated based on weins law as follows: Wavelength = 0.002898/310 = 0.00000934838 m Plugging this into the equation λν = c we get frequency = 299792458 / 0.00000934838 = 32069 Ghz Elsewhere, I see that the resonant...
  12. N

    I Cavity resonances between two long parallel plates

    Consider two rigid and infinitely long parallel plates (say they are of infinite length in X direction, so running from -inf to +inf in X axis) separated by a distance d (say measured in Y-direction). Let the space between the plates be filled up with a fluid that supports acoustic waves. If we...
  13. calvinrose

    B Kill drum head overtones without anything touching the drum head!

    Hi All, I considered filing a patent for this invention, but instead decided to publish it so people could use it to advance the state-of-the-art in drums. You don't need to add tape or pillows to your drum heads to muffle the overtones. Using tape or pillows also kills the strike of the...
  14. Synchronising Metronomes in a Spreadsheet

    Synchronising Metronomes in a Spreadsheet

    The Royal Institution Lectures are on BBC4 and iPlayer now: They'll be on the RI channel a month later.
  15. A

    I Resonance gets sharper just by increasing the resonance freq, why?

    The ##Q## factor of an oscillating system is defined as ##\omega_{r}/\Delta \omega##, where ##\omega_{r}## is the resonant frequency, and ##\Delta \omega## the resonance width. As I understand, ##Q## measures how sharp the resonance curve is. Why is it that the resonance curve gets...
  16. mollwollfumble

    A Coorbital question

    I was working on a proposal for a spacecraft, and suddenly realised that the ideal orbit may be a high inclination type of near-Earth coorbital called a "retrograde satellite" or RS orbit. Do you know of: * A person who can compute 100 years of coorbital stability using three body (sun, earth...
  17. baywa2

    Determine the capacitor value so that this circuit is in resonance

    L=100mh=0.1H ω=10^3 rad/s -> f = 159Hz XL= ωL= 2πfL= 2π*159*0.1= 99.90 Ω Z parallel = [(XL∠90º)*R2] / [(XL∠90º)-R2]= 37.13∠-21.8º XC= 1/ωC= 1/(2 π f C) I dont see how I am supposed to get to C
  18. P

    Understanding resonance in a spring

    I have the equation $$\frac{d^2y}{dt^2} + 5y = 0$$ where I've worked out $$y = Acos(\sqrt5t) + Bsin(\sqrt 5 t)$$ $$y'' = -5Bsin(\sqrt 5 t) $$ using $$y = e^{\lambda x}$$ and using y(0) = 0 (the spring is released from equilibrium) so an external force $$Acos(\omega(t - \phi))$$ is applied so...
  19. A

    Is this an allowed solution? - 2nd order harmonic oscillation

    It is true that at resonance frequency the phase-shift between input and output is 90 degrees, so my mind would think that this is ok. But I am kind of unsure because of the whole dividing by zero part. If this isn't allowed: is there any way to calculate/measure the damping coefficient with...
  20. K

    What is the governing equation of a spring with sinusoidal excitation?

    Hi, Most of the spring vibration lectures assume spring to be fixed on one end and mass on the other end [Example]. In my case, spring has a sinusoidal excitation on one end and mass on other end. Pl. refer the image below. How to get the governing equation? With that I also want to find the...
  21. Edge5

    Resonant MEMS accelerometers

    Hello, Suppose that I have a resonant MEMS accelerometer. It has a suspending beam (resonator) and I want to apply an AC voltage to the beam which will be at beam's resonant(natural) frequency. When I do this, I will create a standing wave pattern of acoustic waves (vibrations) inside the...
  22. john-b

    Resonance of an Air Column

    Homework Statement [/B] When a stream of air is directed over the end of a 40 cm long piece of plastic pipe, open at both ends, a sound is produced. (a) Explain why this occurs (b) If the bottom end of the pipe is covered, what will happen to the pitch of the sound? Explain Homework Equations...
  23. G

    Resonance between spring and pendulum: Different frequencies

    Hi. I have a spring with spring constant 30 N/m and a mass of 0.5 kg. With the mass at the bottom, the spring has the length 58 cm at rest. If I now pull down the mass and release it, it starts with a vertical oscillation, then the spring also starts to swing sideways like a pendulum and the...
  24. W

    Natural/resonant frequency

    Hi all, Wanted to get some insight on a technical level as to what are the most fundamental factors which influence a materials natural frequency? Looking for theory based insight not impirical characteristics.
  25. S

    Vibration of a mass connected via preloaded spring

    The setup: I have a mass (m1)connected to a much, much larger mass (m2) via a preloaded spring. They start out in contact because the preloaded spring holds them together. Now suppose the large mass is subject to vibrations, possibly at the resonance of the structure. Will the two masses...
  26. R

    Stability Order of resonating structures

    I have uploaded the picture of the structures cuz I couldnt figure out how to type. Its vinyl chloride. According to me the order should be I>III>II because I has no charge so it must be most stable in II we have Cl an electronegative element bearing positive charge which makes it unstable...
  27. C

    I Are resonances formed in the scattering of a baryon and a meson?

    Consider the following reaction of strong interaction (in a scattering process) $$n+\pi^+\to \Lambda_0+K^+\tag{1}$$ Then the particle ##\Lambda_0## formed decays with weak interaction $$\Lambda_0\to \pi^+ +p\tag{2}$$ For each decay process I measure the four momenta of ##K^+##, ##\pi^+##...
  28. R

    A Free bar fundamental vibration relationship length to width

    When finding the fundamental for thin bars, the approximate equation ( only refers to the length and thickness when calculating. I'm trying to figure out the frequency and node location along the length and width of the fundamental...
  29. Bassam Shehadeh

    A Nuclear size at resonance states

    I'd appreciate any reference or citation shows what is the change of the nuclear radius at resonance states, especially for 56Fe and 40Ca. Thank you
  30. H

    Frequency for resonance to occur

    Homework Statement That is a speaker. Sound wave is sent out from spesker S into pipe of uniform thickness. Piston P move to left 1st resonance at 0.045 m 2nd resonance at 0.151 m Frequency of the sounx 1620 Hz Piston is stopped at the position that 2nd resonance occur Then, frequency...