Terminology related with Sound
Amplitude
Amplitude, the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It is equal to one-half the length of the vibration path. The amplitude of a pendulum is thus one-half the distance that the bob traverses in moving from one side to the other. waves are generated by vibrating sources, their amplitude being proportional to the amplitude of the source.
For a transverse wave, such as the wave on a plucked string, amplitude is measured by the maximum displacement of any point on the string from its position when the string is at rest. For a longitudinal wave, such as a sound wave, amplitude is measured by the maximum displacement of a particle from its position of equilibrium. When the amplitude of a wave steadily decreases because its energy is being lost, it is said to be damped.
Wavelength
Wavelength, distance between corresponding points of two consecutive waves. “Corresponding points” refers to two points or particles in the same phase—i.e., points that have completed identical FRACTIONS of their periodic motion. Usually, in transverse waves (waves with points oscillating at right angles to the direction of their advance), wavelength is measured from crest to crest or from trough to trough; in longitudinal waves (waves with points vibrating in the same direction as their advance), it is measured from compression to compression or from rarefaction to rarefaction. Wavelength is usually denoted by the Greek letter lambda (λ); it is equal to the speed (v) of a wave train in a medium divided by its frequency (f): λ = v/f.
Frequency of Vibration
Vibration is periodic back-and-forth motion of the particles of an elastic body or medium, commonly resulting when almost any physical system is displaced from its equilibrium condition and allowed to respond to the forces that tend to restore equilibrium.
Vibrations fall into two categories: free and forced.
Free vibrations occur when the system is disturbed momentarily and then allowed to move without restraint. A classic example is provided by a weight suspended from a spring. In equilibrium, the system has minimum energy and the weight is at rest. If the weight is pulled down and released, the system will respond by vibrating vertically.
The vibrations of a spring are of a particularly simple kind known as simple harmonic motion (SHM). This occurs whenever the disturbance to the system is countered by a restoring force that is exactly proportional to the degree of disturbance. In this case, the restoring force is the tension or compression in the spring, which (according to Hooke’s law) is proportional to the displacement of the spring. In simple harmonic motion, the periodic oscillations are of the mathematical form called sinusoidal.
Most systems that suffer small disturbances counter them by exerting some form of restoring force. It is frequently a good approximation to suppose that the force is proportional to the disturbance, so that SHM is, in the limiting case of small disturbances, a generic feature of vibrating systems. One characteristic of SHM is that the period of the vibration is independent of its amplitude. Such systems therefore are used in regulating clocks. The oscillation of a pendulum, for instance, approximates SHM if the amplitude is small.
The frequency of a vibration, measured in Hertz (Hz), is simply the number of to and fro movements made in each second. A tuning fork or piano string vibrating at 256 Hz will produce a pitch of middle C. A greater frequency than this will produce a higher-pitched note and so on. Children will often mix up pitch and loudness believing that a higher pitched sound is a louder one. Higher pitched sounds produce waves which are closer together than for lower pitched sounds.
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Amplitude, wavelength, and frequency are three of the most important properties of waves. They are all related to each other, and they all play a role in determining the characteristics of a wave.
Amplitude is the maximum displacement of a particle from its equilibrium position. In other words, it is the distance between the crest of a wave and the equilibrium position, or the distance between the trough of a wave and the equilibrium position. The amplitude of a wave determines its height. A wave with a large amplitude will be taller than a wave with a small amplitude.
Wavelength is the distance between two successive crests or troughs of a wave. It is also the distance between two successive points on a wave that are in phase with each other. The wavelength of a wave determines its length. A wave with a long wavelength will be longer than a wave with a short wavelength.
Frequency is the number of waves that pass a given point in a given amount of time. It is also the number of times a particle at a given point on a wave goes through its full cycle of motion in a given amount of time. The frequency of a wave determines its pitch. A wave with a high frequency will have a high pitch, while a wave with a low frequency will have a low pitch.
The amplitude, wavelength, and frequency of a wave are all related to each other. The amplitude of a wave is proportional to the square of its frequency. In other words, a wave with twice the frequency will have four times the amplitude. The wavelength of a wave is inversely proportional to its frequency. In other words, a wave with twice the frequency will have half the wavelength.
The amplitude, wavelength, and frequency of a wave can all be affected by the medium through which the wave is traveling. For example, a wave traveling through a solid will have a higher amplitude than a wave traveling through a gas. A wave traveling through a liquid will have a higher frequency than a wave traveling through a gas.
Amplitude, wavelength, and frequency are all important properties of waves. They are all related to each other, and they all play a role in determining the characteristics of a wave.
In addition to amplitude, wavelength, and frequency, there are a few other properties of waves that are worth mentioning. These include:
- Speed: The speed of a wave is the distance it travels in a given amount of time. It is equal to the wavelength divided by the frequency.
- Direction: The direction of a wave is the direction in which it is traveling.
- Phase: The phase of a wave is the position of a particle on a wave relative to its equilibrium position.
- Intensity: The intensity of a wave is the amount of energy it carries. It is proportional to the square of the amplitude.
- Polarization: The polarization of a wave is the direction of its electric field.
These are just a few of the many properties of waves. Waves are a fascinating and complex topic, and there is still much that we do not know about them. However, the properties that we do know about waves can be used to understand and predict their behavior.
Amplitude
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What is amplitude?
Amplitude is the height of a wave, from its lowest point to its highest point. -
What is the relationship between amplitude and loudness?
The higher the amplitude, the louder the sound. -
What is the unit of measurement for amplitude?
The unit of measurement for amplitude is the decibel (dB).
Wavelength
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What is wavelength?
Wavelength is the distance between two consecutive peaks or troughs of a wave. -
What is the relationship between wavelength and frequency?
The shorter the wavelength, the higher the frequency. -
What is the unit of measurement for wavelength?
The unit of measurement for wavelength is the meter (m).
Frequency of Vibration
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What is frequency of vibration?
Frequency of vibration is the number of times a wave vibrates per second. -
What is the relationship between frequency of vibration and pitch?
The higher the frequency of vibration, the higher the pitch. -
What is the unit of measurement for frequency of vibration?
The unit of measurement for frequency of vibration is the hertz (Hz).
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The distance between two consecutive crests or troughs of a wave is called:
(a) Amplitude
(b) Wavelength
(c) Frequency
(d) Period -
The number of waves that pass a given point in a given amount of time is called:
(a) Amplitude
(b) Wavelength
(c) Frequency
(d) Period -
The height of a wave is called:
(a) Amplitude
(b) Wavelength
(c) Frequency
(d) Period -
The time it takes for one complete wave to pass a given point is called:
(a) Amplitude
(b) Wavelength
(c) Frequency
(d) Period -
The higher the amplitude of a sound wave, the:
(a) Louder the sound
(b) Softer the sound
(c) Higher the pitch
(d) Lower the pitch -
The higher the frequency of a sound wave, the:
(a) Louder the sound
(b) Softer the sound
(c) Higher the pitch
(d) Lower the pitch -
The human ear can hear sounds with frequencies between:
(a) 20 Hz and 20,000 Hz
(b) 20 Hz and 200 Hz
(c) 200 Hz and 2000 Hz
(d) 2000 Hz and 20,000 Hz -
Sound waves travel through:
(a) Air
(b) Water
(c) Solids
(d) All of the above -
Sound waves can be reflected, refracted, and diffracted.
(a) True
(b) False -
Sound waves can be used to create images.
(a) True
(b) False