Name: standing wave modes in sound tubes
Uploaded: 2023-05-16T08:18:41.000Z
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K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Physical Science

Waves and Their Applications

PS.PSc.8.4

Modes of Standing Waves: II

Considérez l’air emprisonné à l’intérieur d’un tube ouvert à une extrémité et fermé à l’autre. Si une onde frappe dessus, elle se réfléchit, produisant des ondes stationnaires.
Les conditions limites sont des antinœuds à l’extrémité ouverte, où les molécules d’air sont libres de vibrer, et des nœuds à l’extrémité fermée, où elles ne le sont pas.
Si les deux extrémités étaient fermées, le premier mode possible aurait des nœuds aux deux extrémités. Mais ici, le premier mode possible peut être obtenu en étirant ce motif. La longueur du tube est égale à un quart de la longueur d'onde du mode fondamental.
Pour le premier harmonique, la longueur est égale aux trois quarts de la longueur d’onde. Pour le deuxième harmonique, c’est les cinq quarts de la longueur d’onde, et ainsi de suite.
Ainsi, on trouve que les longueurs d’onde des modes d’onde stationnaire suivent un modèle mathématique donné par n, un entier impair.
Les fréquences correspondantes, ou harmoniques, sont obtenues en termes de vitesse d’onde.

<ol>
	<li>OpenStax. (2019). Physique universitaire Vol. 1. [Version Web]. Extrait de <a href="https://openstax.org/books/university-physics-volume-1/pages/1-introduction">https://openstax.org/books/university-physics-volume-1/pages/1-introduction</a> : sections 16.6 et 17.4 ; pages 829-830 et 872-875.</li>
</ol>

modes de ondes stationnaires : ii

Le point de départ pour exprimer les modes de ondes stationnaires est de comprendre les conditions limites que les ondes doivent suivre. Ces conditions limites sont dérivées de la compréhension physique de la manière dont les ondes stationnaires sont maintenues, c'est-à-dire comment les particules vibrantes du milieu se comportent aux limites qui leur sont imposées.

Pour un tube ouvert à une extrémité et fermé à l'autre rempli d'air, les modes sont tels qu'il y a toujours un antinode à l'extrémité ouverte et un nœud à l'extrémité fermée. De manière intéressante, les fréquences de résonance dépendent de la vitesse du son, qui dépend de la température. Cela peut poser des problèmes perceptibles, par exemple, pour les orgues dans d'anciennes cathédrales non chauffées. C'est aussi la raison pour laquelle les musiciens amènent généralement leurs instruments à vent à température ambiante avant de les jouer.

Les harmoniques d'un tube peuvent être également déduits. Tout d'abord, il faut noter les conditions limites ; les molécules d'air sont libres de vibrer aux deux extrémités. Par conséquent, les deux extrémités sont des antinodes. Cela peut être utilisé pour déterminer la longueur d'onde du mode, qui est égale à un multiple entier de la moitié de la longueur du tube. Les harmoniques suivent le même modèle mathématique que celui des ondes stationnaires sur une corde, qui comporte des nœuds aux deux extrémités.

Modes de ondes stationnaires : II

Le point de départ pour exprimer les modes d’ondes stationnaires est de comprendre les conditions limites que les ondes doivent suivre. Les conditions limites ...

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Education

Enseignement

JoVE Core

Physics

Physique

Unit 1

Unité 1

Waves

Ondes

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

standing wave modes in sound tubes

Standing wave modes in sound tubes depend on the boundary conditions at the ends of the tube. These boundary conditions describe how the air particles can move where the tube is open or closed. They set the pattern the standing wave must follow.

For a tube that is open at one end and closed at the other, the air has an antinode at the open end and a node at the closed end. An antinode is a point of maximum motion, while a node is a point of no motion. The resonant frequencies of the tube also depend on the speed of sound, and the speed of sound depends on temperature.

This temperature effect can create problems in real life. Old unheated cathedrals can cause organ notes to shift because the air temperature changes. Musicians also let wind instruments reach room temperature before playing them.

The harmonics of a tube can be found in a similar way. If the air molecules are free to vibrate at both ends, then both ends are antinodes. In that case, the wavelength of each mode is an integer multiple of half the tube’s length. This pattern matches the harmonics of a standing wave on a string, where both ends are nodes.

Standing Wave Modes in Sound Tubes

travelling waves

Mechanical Waves in Air, Water, and Earth

Mechanical waves carry a disturbance through a medium. They repeat periodically and are often linked with simple harmonic motion. These waves follow Newton's laws and need a material medium to move through. A medium is the substance that carries the wave and provides an elastic restoring force when it is deformed. Water waves, sound waves, and seismic waves are examples of mechanical waves. In water waves, water is the medium. In sound waves, the medium is usually air, but it can also be water.

wave parameters

Reading Wave Motion by Its Features

Wave motion can be described by a few key parameters. Simple mechanical waves repeat over several cycles and can be modeled with sine and cosine functions. A simplified surface water wave is a good example. The water moves up and down, while the wave disturbance travels horizontally through the medium. A floating seagull would move up and down as the crests and troughs pass below it. Crest means the peak of the wave, and trough means the valley. This motion follows simple harmonic motion,...

equations of wave motion

Modeling a Wave on a String

A wave on a string can be modeled with a wavefunction. The string moves up and down in simple harmonic motion and has a period T. As time passes, the sinusoidal wave shifts in the positive x-direction. The sine function is used because it repeats every 2π radians and varies between +A and −A, where A is the amplitude. To describe the string’s y-position, the angle θ is related to position x. The sine function is then multiplied by amplitude A to build the wave model. The model must also...

graphing the wave function

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Wave snapshots, period, and phase help describe a sinusoidal wave moving in the positive x-direction. The wave equation depends on both position and time. That is why it can be shown in more than one way. If time is fixed, such as at t = 0, the graph becomes a snapshot of the wave. This is a displacement versus position graph. It shows the displacement of the particle from equilibrium as a function of position. From this graph, the wavelength can be found. For a transverse wave on a string,...

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Wave Motion: Particle Speed and Curvature

Wave motion in a medium has a constant wave velocity. The particles in the medium do not move at that same constant speed. Their motion is perpendicular to the direction of the wave, which helps separate wave speed from particle speed. Because particle speed changes, the particles must also have acceleration. The particle velocity can be found by taking the partial derivative of the position equation with respect to time. Then the acceleration comes from taking the partial derivative of the...

speed of a transverse wave

How String Tension Changes Wave Speed

The speed of transverse waves on a string depends on the string’s tension and its mass per unit length. A string with more tension has stronger restoring forces. Those forces help pull the string back to straight after it is disturbed, so the wave moves faster. Mass per unit length is the mass of a string divided by its length. It is also called linear density. Strings on a guitar can have different thicknesses even when they are made of similar material, so they can have different linear...

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problem-solving: tuning of a guitar string

problem-solving-tuning-of-a-guitar-string

Guitar String Waves and Musical Notes

Guitar string waves depend on linear mass density, tension, and string length. Linear mass density means the mass per unit length of the string. When the density stays constant along the string, it equals the total mass divided by the total length. Changing this linear density can change the wave speed. Tension also affects the speed of transverse waves along a guitar string. The fundamental frequency of the string depends on its length as well. When a string is held on a fret, its effective...

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kinetic and potential energy of a wave

How Waves Transfer Energy

Waves transfer energy through motion in the air, water, and ground. That energy can have real effects. Earthquake waves can shake large concrete buildings until they fall. Loud sound waves can damage nerve cells in the inner ear and lead to permanent hearing loss. Ocean waves can also wear away beaches. In mechanical waves, energy depends on amplitude and frequency. Amplitude is the height or strength of the wave. Large-amplitude earthquakes cause larger ground movement. Loud sounds come from...

energy and power of a wave

Wave Intensity and Energy Transfer

Wave intensity and energy transfer describe how waves carry energy from one place to another. The total energy in a wavelength is the sum of potential energy and kinetic energy. The rate at which that energy moves is called power, which is the total energy divided by the time needed to transfer it. For a sinusoidal wave, energy and power both depend on the square of the amplitude and the angular frequency. That means a larger amplitude or a higher angular frequency gives a greater energy...

interference and superposition of waves

Wave Interference Patterns in Physics

Wave interference patterns form when two waves of the same nature occupy the same region at the same time. The combined effect is the sum of the individual wave effects. Interference does not mean that one wave changes how the other wave travels. This idea applies to mechanical waves, including sound waves, waves on a string, and surface water waves. Mechanical waves move through a medium, so interference shows up as the algebraic sum of particle displacements in that medium. The same...

reflection of waves

Wave Reflection at Fixed and Free Boundaries

Wave reflection happens when a wave reaches a boundary between two media and bounces back. A familiar example is an echo, where sound waves in air reflect from a cliff. Sound waves are longitudinal waves, while a pulse on a string is a transverse wave. A pulse on a string tied to a wall reflects when it reaches the fixed end. The wall acts as a boundary that cannot move with the oscillation. By Newton’s third law, the string pushes on the wall and the wall pushes back with an equal and...

propagation of waves

Wave Reflection and Transmission

Wave reflection and transmission happen when a wave moves from one medium to another. At the boundary, part of the wave can bounce back into the first medium, and part can pass into the second medium. The interface between the two media then acts like a boundary that is neither fixed nor free. The wave behavior depends on the change in linear mass density of the strings. When a wave travels from a string with low linear mass density to a string with high linear mass density, the reflected wave...

standing waves

Wave Interference in Strings and Air Columns

Wave interference in strings and air columns can create standing waves that seem to vibrate in place. A standing wave may appear on the surface of a glass of milk kept in a refrigerator. The refrigerator motor sends vibrations into the milk, and the wave moves up and down without seeming to travel across the surface. Standing waves form when two or more identical moving waves travel in opposite directions. As the waves pass through each other, their disturbances add together. When the waves...

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modes of standing waves - i

Standing Wave Harmonics in Strings and Buildings

Standing waves and resonance can be seen in both earthquakes and strings. Earthquake waves can make a building vibrate for several seconds when the driving frequency matches the building’s natural frequency of vibration. That resonance can cause one building to collapse while nearby buildings stay standing. Building height also matters because it can match the condition needed to form a standing wave at that height. In many cases, buildings of one height are damaged while taller buildings...

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modes of standing waves: ii

Standing wave modes in sound tubes depend on the boundary conditions at the ends of the tube. These boundary conditions describe how the air particles can move where the tube is open or closed. They set the pattern the standing wave must follow. For a tube that is open at one end and closed at the other, the air has an antinode at the open end and a node at the closed end. An antinode is a point of maximum motion, while a node is a point of no motion. The resonant frequencies of the tube also...

key terms and concepts

Explore standing wave modes in sound tubes, including node and antinode boundary conditions, resonant frequency, temperature effects, and harmonics in tubes.

Standing Wave Modes in Sound Tubes | JoVE K12

physics

JoVE Core Physique présente plusieurs branches de la physique fondamentale grâce à des vidéos animées concises et faciles à comprendre ; cela inclut: la cinématique, la dynamique, la mécanique des fluides, la mécanique statique, les ondes et l'acoustique. En parallèle, les vidéos de scientifiques à l'action démontrent l'application de concepts associés à ces domaines dans des expériences de recherche classiques et originales réalisées dans des laboratoires modernes du monde entier.

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Waves and Their Applications in Technologies for Information Transfer

PS.Phy.7.3

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Wave properties

Tennessee Academic Standards

High School

PHYS.PS4.3

PHYS.PS4.4

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

HS-PS4-1

Alabama Course of Study Science

9-12.PS.2.2.e

Next Generation Science Standards

HS-PS4-3

Florida Department of Education

SC.912.P.10

SC.912.P.10.20

Texas Essential Knowledge and Skills

PHYS.8

PHYS.8.D

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South Carolina College and Career Ready Science Standards

P-PS4-3

new-york-state-science-learning-standards

New York State Science Learning Standards

HS. Waves and Electromagnetic Radiation

HS-PS4-1.

Travelling Waves

A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. ...

Wave Parameters

The simplest mechanical waves are associated with simple harmonic motion and repeat themselves for several cycles. These simple harmonic waves can be ...

Equations of Wave Motion

Mathematically, the motion of a wave can be studied using a wavefunction. Consider a string oscillating up and down in simple harmonic motion, having a ...

Graphing the Wave Function

Consider the wave equation for a sinusoidal wave moving in the positive x-direction. The wave equation is a function of both position and time. From the ...

Velocity and Acceleration of a Wave

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Speed of a Transverse Wave

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Problem-Solving: Tuning of a Guitar String

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Kinetic and Potential Energy of a Wave

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Energy and Power of a Wave

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Carry out investigations to explain the quantitative and qualitative relationships among wave frequency, wave velocity, wavelength, and wave energy.

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Use models to compare the characteristics of mechanical and electromagnetic waves.

PS.PSc.8.2

Interference and Superposition of Waves

When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect ...

Reflection of Waves

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Propagation of Waves

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Sound Waves: Interference

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Interference: Path Lengths

Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two ...

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Use models to explain the wave interactions of reflection, refraction, diffraction, and interference.

PS.PSc.8.3

Standing Waves

Sometimes waves do not seem to move; rather, they just vibrate in place. Unmoving waves can be seen on the surface of a glass of milk kept in a ...

Modes of Standing Waves - I

A close look at earthquakes provides evidence for the conditions appropriate for resonance, standing waves, and constructive and destructive interference. ...

The starting point for expressing the modes of standing waves is understanding the boundary conditions that the waves must follow. The boundary conditions ...

Obtain, evaluate, and communicate information to explain how instruments that transmit and detect waves are used in everyday life.

Analyze the nature of waves and their applications.

Standing Wave Modes in Sound Tubes

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