What is Stationary waves: Definition and 33 Discussions

In physics, a standing wave, also known as a stationary wave, is a wave which oscillates in time but whose peak amplitude profile does not move in space. The peak amplitude of the wave oscillations at any point in space is constant with time, and the oscillations at different points throughout the wave are in phase. The locations at which the absolute value of the amplitude is minimum are called nodes, and the locations where the absolute value of the amplitude is maximum are called antinodes.
Standing waves were first noticed by Michael Faraday in 1831. Faraday observed standing waves on the surface of a liquid in a vibrating container. Franz Melde coined the term "standing wave" (German: stehende Welle or Stehwelle) around 1860 and demonstrated the phenomenon in his classic experiment with vibrating strings.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling in opposite directions. The most common cause of standing waves is the phenomenon of resonance, in which standing waves occur inside a resonator due to interference between waves reflected back and forth at the resonator's resonant frequency.
For waves of equal amplitude traveling in opposing directions, there is on average no net propagation of energy.

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  1. jaumzaum

    B Node Placement in Stationary Waves on Pool Surfaces

    Do stationary waves in a pool need to necessarily have nodes at the initial/final points where the wave hits the wall? I'm really asking this because the walls does not seem to be a physical blocker, like a fixed end of a rope that is tied. Considering friction I would say that some energy...
  2. jaumzaum

    I Stationary waves in a vertical rope

    I was wondering if we could produce stationary waves in a vertical rope. There is a nice result we can get from a vertical rope that the pulse created from the lower extremity travels upwards with acceleration g/2 and the pulse created in the upper extremity travels downwards with acceleration...
  3. B

    June 2005 aqa physics paper question on stationary waves

    A couple of questions on this. How would the sound get reflected back from the surface of the water? And therefore create a stationary wave would the sound not travel though the water at a faster speed then reflect back and intefere? Or does a small amount of the sound reflect back? Part B...
  4. J

    Why do Harmonics Decay Faster than the Fundamental?

    When looking at the FFT spectrum of a sonometer, I noticed that the harmonics decayed faster than the fundamental. Why is this?
  5. G

    How harmonics are produced in a guitar string?

    My question is simply 'are all notes produced in a guitar produced by first harmonics?', but I will clarify what made me ask this question. Now, if you have a wave driver you can make several harmonics in a string by increasing the frequency of the machine. In a guitar string, however, it does...
  6. L

    Phase difference and Standing waves vs Progressive waves

    and Homework Statement Ok, so I am doing As physics at the moment and have been left confused by stationary waves. I have read that between adjacent nodes/ even numbers the phase difference is always 0 and between numbers of does it is pi radians. So in the attatched image why is my textbook...
  7. M

    Conditions for waves to be coherent?

    Homework Statement Hello, For two waves to be coherent, they must have the same frequency right? Does this on its own implies a constant phase different between any point on one wave and any on the other. So, for example, if we had two waves with different wavelengths and velocities but equal...
  8. S

    Fundamental frequency change because of bouyant force

    Homework Statement A rope has an end fixed and the other is passing through a pulley and has a body attached to it. The fondamental frequency of the rope is initially ##f_1=400 Hz##. If the body is then put in water the fondamental frequency of the rope becomes ##f_2=345 Hz##. If the linear...
  9. S

    Bouncing ball and Doppler effect

    Homework Statement Consider two parallel walls perfectly reflective placed at the distance ##d = 0.8 m ##. A ball, provided with a device through which are emitted continuously frequency sound waves equal to ##f_0=430 Hz##, is launched from one wall to another. It moves with constant velocity...
  10. M

    Stationary waves - why same amplitude etc?

    Homework Statement Hi, In my textbook, it says that waves superposing to form stationary waves, in addition to being in opposite directions, should have the same frequency and ideally the same amplitude - why the 'ideally' and why is having the same amplitude important? Is it because then we...
  11. toforfiltum

    How to maintain the same stationary wave pattern?

    Homework Statement Homework Equations not sure The Attempt at a Solution The answer is C, though I answered B. I don't understand why C is the answer.I thought that to maintain the same stationary wave pattern, I must maintain the speed of the stationary wave, and one way to do this is by...
  12. Physics_Lovvee

    Can Standing Waves Have Both Transverse and Longitudinal Components?

    Can standing waves be both transverse and longitudinal?
  13. bananabandana

    Are Kinetic and Potential Energy Densities Equal in Stationary Waves?

    Homework Statement Show that the potential and kinetic energy densities for a stationary wave are not equal. Homework Equations A) The 1-D Wave Equation: $$ \frac{\partial^{2} \psi}{\partial x^{2}} = \frac{1}{v^{2}} \frac{\partial^{2}\psi}{\partial t^{2}}$$ B) The general form of a stationary...
  14. A

    Stationary waves in composite strings

    Dear All, I was reading the concept of stationary waves in composite string ABC made up of joining two strings AB AND BC with different mass per unit length and a joint at 'B'.the two ends of the composite string are clamped at 'A' and 'C' and a transverse wave is set up by an external source...
  15. A

    Nodes and antinodes in stationary waves

    Dear Friends, in my textbook it is written that when a stationary wave is formed in a string which is clamped at one end and free at the other end then a node is produced at the clamped end and an Anti-node is produced at the free end.the explanation given is that since at clamped particle...
  16. A

    Stationary Waves: Explaining Amplitude of Wave

    Dear All, when two waves y=Asin(wt-kx) and y=A(sinwt+kx) superpose the stationary wave is formed with equation y = 2Asinkxcoswt.in my textbook they take 2Asinkx as amplitude of wave.why didn't they take 2Acoswt as amplitude of stationary wave.please explain me in detail. I will be thankful...
  17. M

    Calculate number of nodes in stationary waves

    Homework Statement Hi guys I have this problem that I can't solve.. Suppose to have this situation: when M=16kg the cord vibrates in one of its normal ways of oscillation. when M=6.25 we have the same frequency but 3 more nodes. How many are the nodes of the stationary wave in the first...
  18. Nemo's

    Stationary waves and Resonance

    I don't really understand the relationship between the wavelength of a stationary wave and the length of the air column. I also don't know what happens when the wavelength changes. I would appreciate it if you could help.
  19. D

    A problem about stationary waves ?

    Homework Statement a violin string of length 40 cm and mass 1.2 gm has a frequency 500 hz when it produces fundamental tone where should you place your finger to increase frequency to 650 hz Homework Equations frequency = n/2L . sqrt FT/ML The Attempt at a Solution i just want to...
  20. P

    Stationary Waves - Effect of Frequency and Amplitude

    Hi, As part of my Physics Class, we created a spreadsheet that animates to waves moving in opposite directions to illustrate standing waves. In order to test we were told to put the same values of amplitude, wavelength and speed (frequency was calculated from wavelength and speed) for both...
  21. N

    Whats the difference between progressive wave and stationary waves ?

    Wats the difference between progressive wave and stationary waves ?
  22. E

    Phase difference in Stationary waves

    I have a question. Why is it that the phase difference between two oscillating points which are both located in between two ADJACENT nodes is zero ? Can someone prove this via a calculation ?
  23. A

    Stationary Waves: Equations for Standing Waves

    Stationary waves... Homework Statement Which of the following equations can form stationary waves... 1. y=Asin(wt-kx) 2. y=Acos(wt-kx) 3. y=Asin(wt+kx) 4. y=Acos(wt+kx) Homework Equations The Attempt at a Solution Answer is 1,3 and 2,4 which is obviously correct...But why...
  24. I

    Solving Stationary Waves Homework Problems

    Homework Statement A primitive question yet I can't am having difficulty in solving it. http://img524.imageshack.us/i/confusedu.png" Homework Equations F = 1/T The Attempt at a Solution The only value given is the difference in the time frame of the respective waves.The only other...
  25. Z

    Meaning of Phase in stationary waves

    What is the exact meaning of the statement " In a standing wave, all the particles are in the same phase "? Phase, ϕ = 2(pi)x/λ If we consider the node as origin, different particles have different x values. Then how come the phase is same for all?
  26. F

    Stationary Waves: Reflection & Odd Harmonics

    hi there i just wanted to know that how are waves reflected in an open air column and what do we mean about odd harmonics? thank you
  27. P

    Why do stationary waves not act like destructive ones?

    Homework Statement To create a standing wave, two progressive waves must be traveling in opposite directions along the same line. They also must have the same frequency, wavelength and therefore speed. Destructive waves are similar only they travel in opposite directions. Why does it...
  28. P

    Stationary waves energy problem

    hi, i had this doubt regarding stationary waves consider a string held between two points and vibrating in fundamental mode, so that there will be nodes at the fixed points. then consider the datum of the potential energy at the mean position. now when all particles have gone up by their...
  29. G

    Question about stationary waves

    I have a question about stationary waves. Anti-nodes are where waves are in phase and nodes are where the waves are out of phase, right? But don't the waves have to be in phase for a stationary wave to be produced (so there wouldn't be any nodes)? Or do they only have to be coherent?
  30. T

    Understanding Stationary Waves in Open and Closed Tubes

    Homework Statement For a tube with one end open and one closed a) Draw a labelled sketch of the stationary wave patter for (i) the fundamental and (ii) the next highest mode. b)describe the physical quantity graphed (as the verticle axis, i.e. the dependent variable) c) clearly explain...
  31. D

    Stationary Waves: Finding Minimum Intensity Distance

    stationary waves, urgent! helllloo. i'm having a major exam tomorrow and i stumbled across this question just now..would appreciate all your help! Two loudspeakers S1 and S2 are placed a distance 4.0m apart facing each other. The loudspeakers produce sound waves of frequency 165 Hz in...
  32. Y

    Stationary Waves on Strings and in Pipes?

    Hey! Was just wondering if someone could shed some light on the whole stationary waves thing. I've done about them in my A-Level Physics course and I can't for the life of me figure out what it's about. I mean, why can you only have a certain number of nodes, hence certain frequencies...
  33. M

    Explaining Stationary Waves: Ideas & Analogy

    How would be a good way of explaining Sationary Waves to somebody who does not know what they are? I'm talking analogys, presentations, ideas. I have a good knowledge of them, but am struggling to explain them to my peers.