Add to collection. Nature of science The illustrations in this article are models of waves. Related content The article Waves and energy — wave basics provides additional information about transverse and longitudinal waves, including vocabulary.
Go to full glossary Add 0 items to collection. Download 0 items. Twitter Pinterest Facebook Instagram. Email Us. See our newsletters here. Would you like to take a short survey? This survey will open in a new tab and you can fill it out after your visit to the site. Yes No. In longitudinal and transverse waves, all the particles in the entire bulk of the medium move in a parallel and a perpendicular direction respectively relative to the direction of energy transport.
In a surface wave, it is only the particles at the surface of the medium that undergo the circular motion. The motion of particles tends to decrease as one proceeds further from the surface. Any wave moving through a medium has a source. Somewhere along the medium, there was an initial displacement of one of the particles.
For a slinky wave, it is usually the first coil that becomes displaced by the hand of a person. For a sound wave, it is usually the vibration of the vocal chords or a guitar string that sets the first particle of air in vibrational motion. At the location where the wave is introduced into the medium, the particles that are displaced from their equilibrium position always moves in the same direction as the source of the vibration.
So if you wish to create a transverse wave in a slinky, then the first coil of the slinky must be displaced in a direction perpendicular to the entire slinky. Similarly, if you wish to create a longitudinal wave in a slinky, then the first coil of the slinky must be displaced in a direction parallel to the entire slinky. Electromagnetic versus Mechanical Waves.
Another way to categorize waves is on the basis of their ability or inability to transmit energy through a vacuum i. Categorizing waves on this basis leads to two notable categories: electromagnetic waves and mechanical waves. An electromagnetic wave is a wave that is capable of transmitting its energy through a vacuum i. Electromagnetic waves are produced by the vibration of charged particles. Electromagnetic waves that are produced on the sun subsequently travel to Earth through the vacuum of outer space.
Were it not for the ability of electromagnetic waves to travel to through a vacuum, there would undoubtedly be no life on Earth. All light waves are examples of electromagnetic waves.
Light waves are the topic of another unit at The Physics Classroom Tutorial. While the basic properties and behaviors of light will be discussed, the detailed nature of an electromagnetic wave is quite complicated and beyond the scope of The Physics Classroom Tutorial.
A mechanical wave is a wave that is not capable of transmitting its energy through a vacuum. Mechanical waves require a medium in order to transport their energy from one location to another. A sound wave is an example of a mechanical wave. Sound waves are incapable of traveling through a vacuum. Slinky waves, water waves, stadium waves, and jump rope waves are other examples of mechanical waves; each requires some medium in order to exist. A slinky wave requires the coils of the slinky; a water wave requires water; a stadium wave requires fans in a stadium; and a jump rope wave requires a jump rope.
The above categories represent just a few of the ways in which physicists categorize waves in order to compare and contrast their behaviors and characteristic properties. This listing of categories is not exhaustive; there are other categories as well. The most common pressure wave is the sound wave. Sound waves are created by the compression of a medium, usually air. Longitudinal sound waves are waves of alternating pressure deviations from the equilibrium pressure, causing local regions of compression and rarefaction.
Matter in the medium is periodically displaced by a sound wave, and thus oscillates. When people make a sound, whether it is through speaking or hitting something, they are compressing the air particles to some significant amount.
By doing so, they create transverse waves. When people hear sounds, their ears are sensitive to the pressure differences and interpret the waves as different tones.
Water waves can be commonly observed in daily life, and comprise both transverse and longitudinal wave motion. Water waves, which can be commonly observed in our daily lives, are of specific interest to physicists. Describing detailed fluid dynamics in water waves is beyond the scope of introductory physics courses.
Although we often observe water wave propagating in 2D, in this atom we will limit our discussion to 1D propagation.
The uniqueness of water waves is found in the observation that they comprise both transverse and longitudinal wave motion. As a result, the particles composing the wave move in clockwise circular motion, as seen in. Oscillatory motion is highest at the surface and diminishes exponentially with depth. Waves are generated by wind passing over the surface of the sea. As long as the waves propagate slower than the wind speed just above the waves, there is an energy transfer from the wind to the waves.
Both air pressure differences between the upwind and the lee side of a wave crest, as well as friction on the water surface by the wind making the water to go into the shear stress , contribute to the growth of the waves.
In the case of monochromatic linear plane waves in deep water, particles near the surface move in circular paths, creating a combination of longitudinal back and forth and transverse up and down wave motions. When waves propagate in shallow water where the depth is less than half the wavelength , the particle trajectories are compressed into ellipses. As the wave amplitude height increases, the particle paths no longer form closed orbits; rather, after the passage of each crest, particles are displaced slightly from their previous positions, a phenomenon known as Stokes drift.
Plane wave : We see a wave propagating in the direction of the phase velocity. The wave can be thought to be made up of planes orthogonal to the direction of the phase velocity.
Since water waves transport energy, attempts to generate power from them have been made by utilizing the physical motion of such waves. Although larger waves are more powerful, wave power is also determined by wave speed, wavelength, and water density. Deep water corresponds with a water depth larger than half the wavelength, as is a common case in the sea and ocean.
In deep water, longer-period waves propagate faster and transport their energy faster. The deep-water group velocity is half the phase velocity. In shallow water for wavelengths larger than about twenty times the water depth as often found near the coast , the group velocity is equal to the phase velocity. These methods have proven viable in some cases but do not provide a fully sustainable form of renewable energy to date.
Water waves : The motion water waves causes particles to follow clockwise circular motion. This is a result of the wave having both transverse and longitudinal properties. Waves are defined by its frequency, wavelength, and amplitude among others. They also have two kinds of velocity: phase and group velocity. Waves have certain characteristic properties which are observable at first notice.
The first property to note is the amplitude. The amplitude is half of the distance measured from crest to trough. We also observe the wavelength, which is the spatial period of the wave e. The frequency of a wave is the number of cycles per unit time — one can think of it as the number of crests which pass a fixed point per unit time. Mathematically, we make the observation that,.
Frequencies of different sine waves. Conversely we say that the purple wave has a high frequency. Note that time increases along the horizontal. After a review none of the projects were selected to progress further and, as of , EECA believe that the abundance of cheaper renewable energy resources in New Zealand makes it unlikely marine energy will contribute to the national grid in the foreseeable future.
Investigations into harnessing the energy of ocean waves continues in other countries. From to , as part of a Sustainable Seas Innovation Fund project, NIWA investigated whether generating electricity from the strong tidal currents within the Cook Strait would be viable for Aotearoa. To find out more, see Energy from tidal currents — Kick-starting a new marine industry with huge potential from NIWA's website. Use a Mexican wave to demonstrate how waves transfer energy and to help your students visualise the wave behaviours of reflection, constructive interference and shoaling.
Use an interactive or paper-based Venn diagram to illustrate the key similarities and differences between tsunami waves and surf waves. Explore more about waves, such as sound and energy by browsing the resources under our waves concept.
In NIWA ran a webinar: A step closer to a future powered by tidal current energy , in which the results of the Energy from tidal currents project are presented. This project investigated the viability of generation electricity from the strong tidal currents within Cook Strait. Find out more about using waves as an energy source in this Wikipedia article.
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