drop (liquid)

Information about drop (liquid)

Droplet can also refer to an applet in AppleScript which accepts files "dropped" onto it


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Water dropping from a tap.


A drop or droplet is a small volume of liquid, bounded completely or almost completely by free surfaces.

Surface tension

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The pendant drop test illustrated.


The simplest way to form a drop is to allow liquid to flow slowly from the lower end of a vertical tube of small diameter. When the pendant drop exceeds a certain size it is no longer stable and detaches itself. Drops may also be formed by the condensation of a supercooled vapor or by atomization of a larger mass of liquid. The mass m (or weight mg) of the largest drop that can hang from the end of a tube of radius a can be found from the formula



where λ is the surface tension of the liquid, α is the angle of contact with the tube, and g is the acceleration due to gravity. This relationship is the basis of a convenient method of measuring surface tension, commonly used in the petroleum industry.

Optics

Due to the different refractive index of water and air, refraction and reflection occur on the surfaces of raindrops, leading to rainbow formation.

Sound

The major source of sound when a droplet hits a liquid surface is the resonance of excited bubbles trapped underwater. These oscillating bubbles are responsible for most liquid sounds, such as running water or splashes, as they actually consist of many drop-liquid collisions.[1][2]

Gallery




Impact of a drop of water.

Backjet from drop impact.

A drop of water hitting a metal surface.

A drop of water hitting a wet metal surface and ejecting more droplets, which become water globules and skim across the surface of the water.

A drop of water on a leaf.

A triple backjet after impact.


See also

References

1. ^ Prosperetti, Andrea; Oguz, Hasan N. (1993). "The impact of drops on liquid surfaces and the underwater noise of rain" (PDF). Annual Review of Fluid Mechanics 25: 577-602. DOI:10.1146/annurev.fl.25.010193.003045. Retrieved on 2006-12-09. 
2. ^ Rankin, Ryan C. (June 2005). Bubble Resonance. The Physics of Bubbles, Antibubbles, and all That. Retrieved on 2006-12-09.

External links

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Liquid is one of the four principal states of matter. A liquid is a fluid that can freely form a distinct surface at the boundaries of its bulk material.

Characteristics

A liquid's shape is determined by, not confined to, the container it fills.
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pendant (from Old French) is a hanging object, generally attached to a necklace or an earring. In modern French this is a word meaning “during” (also the gerund form of "hanging"). Pendants have several purposes:
  • ornamentation
  • identification (i.e.

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Condensation is the change in matter of a substance to a denser phase, such as a gas (or vapor) to a liquid.[1] Condensation commonly occurs when a vapor is cooled to a liquid, but can also occur if a vapor is compressed (i.e.
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Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid.

Description

A liquid below its freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form.
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Vapor or vapour (see spelling differences) is the gas phase component of another state of matter (e.g. liquid or solid) which does not completely fill its container. It is distinguished from the pure gas phase by the presence of the same substance in another state of matter.
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Atomization (British English: atomisation) is conversion of bulk liquid into a spray or mist (i.e. collection of drops), often by passing the liquid through a nozzle.
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Surface tension is an effect within the surface layer of a liquid that causes that layer to behave as an elastic sheet. It allows insects, such as the water strider (pond skater, UK), to walk on water.
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contact angle is the angle at which a liquid/vapor interface meets the solid surface. The contact angle is specific for any given system and is determined by the interactions across the three interfaces.
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The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. For example, typical glass has a refractive index of 1.
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Water is a common chemical substance that is essential to all known forms of life.[1] In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor.
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Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity. It contains roughly (by molar content/volume) 78% nitrogen, 20.95% oxygen, 0.93% argon, 0.
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Refraction is the change in direction of a wave due to a change in its speed. This is most commonly seen when a wave passes from one medium to another. Refraction of light is the most commonly seen example, but any type of wave can refract when it interacts with a medium, for
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Reflection is the change in direction of a wave front at an between two dissimilar media so that the wave front returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves.
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Rain is a type of precipitation, a product of the condensation of atmospheric water vapor that is deposited on the earth's surface. It forms when separate drops of water fall to the Earth's surface from clouds.
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Rainbows are optical and meteorological phenomena that cause a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere.
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Globule can refer to:
  • Bok globule
  • Molten globule
  • Globule (CDN)
  • Drop (liquid)
  • Antibubbles of liquid on top of a surface of liquid

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Rain is a type of precipitation, a product of the condensation of atmospheric water vapor that is deposited on the earth's surface. It forms when separate drops of water fall to the Earth's surface from clouds.
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Portable Document Format (PDF)

Adobe Reader displaying a PDF in Microsoft Windows Vista
File extension: .pdf
MIME type: application/pdf
Type code: 'PDF ' (including a single space)
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digital object identifier (or DOI) is a permanent identifier given to a document, which is not related to its current location. A typical use of a DOI is to give a scientific paper or article a unique identifying number that can be used by anyone to locate details of the paper, and
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