An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 52 Search : force
"nongravitational forces"
  "نیروهای ِ ناگرانشی"   
"niruhâ-ye nâgerâneši" (#)

Fr.: "forces non-gravitationnelles"   

The forces of jets from a comet's nucleus that can cause a rocket-like effect and alter a comet's direction of motion slightly.

non-; → gravitational; → force.

adhesive force
  نیروی ِ آدوسش   
niru-ye âduseš

Fr.: force adhésive   

The force of → attraction between molecules of different substances; for example, the force between the molecules of a solid and a liquid. When water is poured on clean glass, it tends to spread, forming a thin, uniform film over the surface. This is because the adhesive forces between water and glass are strong enough to pull the water molecules out of their spherical formation and hold them against the surface of the glass, thus avoiding the repulsion between like molecules.

adhesive; → force.

aerodynamic force
  نیروی ِ هواتوانیک   
niru-ye havâtavânik

Fr.: force aérodynamique   

The force exerted by a gaseous fluid upon a body completely immersed in it caused by their relative motion. The components of aerodynamic force are: → lift and → drag.

aerodynamic; → force.

attractive force
  نیروی ِ درکشنده   
niru-ye darkašandé

Fr.: force attractive   

A physical force (→ gravitational, → electric, → magnetic, etc.) by which a body attracts another.

attractive; → force.

buoyant force
  نیروی ِ بالاران   
niru-ye bâlârân

Fr.: poussée d'Archimède   

The force that causes immersed bodies to float or rise to the surface of a liquid or upward in a gas. Buoyant force is produced by → gravity and density differences. Same as → buoyancy.

From buoy (current meaning) "a float moored in water to mark a location," from M.E. boye, from O.Fr. buie or M.Du. boeye, from L. boia "fetter, chain" + suffix -ant; → force.

central force
  نیروی ِ مرکزی   
niru-ye markazi

Fr.: force centrale   

A → force that is always directed toward a fixed point and whose → magnitude depends only on the distance from that point. Mathematically, F is a central force if and only if: F = f(r)r1 = f(r)r/r, where r1 = r/r is a unit → vector in the direction of r. If f(r) < 0 the force is said to be → attractive toward the source. If f(r) > 0 the force is said to be → repulsive from the source. In other words, a central force is one whose → potential, V(r), depends only on the → distance from the source. → Gravitational force and → electrostatic force are central, with V(r)∝ 1/r.

central; → force.

centrifugal force
  نیروی ِ مرکزگریز   
niru-ye markaz-goriz (#)

Fr.: force centrifuge   

A force in a rotating reference frame directed outward from the axis of rotation.

centrifugal; → force.

centripetal force
  نیروی ِ مرکزگرا   
niru-ye markaz-gerâ (#)

Fr.: force centripète   

The force exerted on an object in → circular motion which is directed toward the center and keeps the body in motion. Centripetal force produces → centripetal acceleration, according to → Newton's second law: Fc = mac. Its direction is always inward along the → radius vector, and its magnitude is given by: Fc= mac = mvt2/r = mω2r.

centripetal; → force.

cohesive force
  نیروی ِ همدوسش   
niru-ye hamduseš

Fr.: force cohésive, ~ de cohésion   

The force of → attraction between the molecules of the same substance.

cohesive; → force.

collinear forces
  نیروهای ِ هم-خط   
niruhâ-ye ham-xatt

Fr.: forces collinéaires   

A system of two or more forces that lie along the same → line of action.

collinear; → force.

concurrent forces
  نیروهای ِ همرس   
niruhâ-ye hamras (#)

Fr.: forces concourantes   

A system of forces applied to a → rigid body in such manner that their lines of action intersect at a single point. A system of concurrent forces acting on a rigid body can be replaced by an equivalent force applied at the same point. → line of action.

concurrent M.E., from M.Fr., from L. concurrentem, pr.p. of concurrere "to run together," from com- "together" + currere "to run," → current; → force.

Niruhâ, plural of niru, → force; hamras, literally "coming, reaching together," from ham-, → com-, + ras "coming, comer, reaching," present stem of rasidan "to arrive; to attain" (Mid.Pers. rasidan "to arrive, to mature;" O.Pers./Av. rasa- present stem of ar- "to move, go or come toward;" cf. Skt. ar-, rcchati "reaches;" Gk. erkhomai "to go, to reach;" L. oriri "to rise").

coplanar forces
  نیروهای ِ هم-هامن   
niruhâ-ye ham-hâmon

Fr.: forces coplanaires   

A system of forces acting on a body that all are in the same plane.

com- + planar adj. from → plane.

Coriolis force
  نیروی ِ کوریولیس   
niru-ye Coriolis (#)

Fr.: force de Coriolis   

An apparent, rather than real, force exerted on a body when it moves in a rotating → reference frame. Same as the → Coriolis effect.

Coriolis effect; → force.

Coulomb force
  نیروی ِ کولن   
niru-ye Coulomb (#)

Fr.: force de Coulomb   

An attractive or repulsive → electrostatic force between objects bearing electric charge, as described by → Coulomb's law. If the charges are of opposite sign, then the force is attractive; if thy are of the same sign, the force is repulsive.

Coulomb; → force.

electromagnetic force
  نیروی ِ برقامغناتی   
niru-ye barqâmeqnâti

Fr.: force électromagnétique   

The fundamental force that is associated with electric and magnetic fields. One of the four fundamental forces of nature, it is carried by photons.

electromagnetic; → force.

electromotive force (EMF)
  نیروی ِ برقران   
niru-ye barqrân (#)

Fr.: force électromotrice   

The force, analogous to a pressure, which maintains a flow of electricity through a closed circuit. It is the algebraic sum of the → potential differences acting in the circuit. The unit of electromotive force is the → volt.

From → electro- + motive, from M.E., from M.Fr., from O.Fr. motif, from M.L. motivus "moving, impelling," from L. motus, p.p. of movere "to move," → motion; → force.

Niru, → force; barqrân, literally "driving electricity," from barq, → electro- + rân present stem of rândan, → drive.

electroweak force
  نیروی ِ برقا نزار، ~ برقا کمزور   
niru-ye barqânezâr, ~ barqâkamzur

Fr.: force électrofaible   

The force that takes part in an → electroweak interaction.

electroweak; → force.

exchange force
  نیروی ِ گهولی   
niru-ye gahuli

Fr.: force d'échange   

The force that governs the exchange of particles in the interaction between bodies. → exchange particle.

exchange, → force.

field of force
  میدان ِ نیرو   
meydân-e niru (#)

Fr.: champ de force   

The region of → space surrounding a body, such as a mass of → matter, a → charged particle, or a → magnet, within which it can exert a → force on another similar body not in contact with it.

field; → force.

force
  نیرو   
niru (#)

Fr.: force   

1) The cause of a change in motion or shape of a body.
2) A → vector quantity defined by → Newton's second law as the rate of change of → momentum or, equivalently, as the product of → mass and → acceleration. A force is completely specified by giving its magnitude, direction, and point of application. In mechanics, force represents the quantitative measure of the mechanical interaction of material bodies.

From O.Fr. force, from L.L. fortia, from neut. pl. of L. fortis "strong," from forctus, from PIE base *bhergh- "high" (cf. Av. barəz- "high, mount," barezan- "height;" O.Pers. baršan- "height;" Mod.Pers. borz in (the mountain chain) Alborz, and borz "height, magnitude," bâlâ "up, above, high, elevated, height," Lori dialect berg "hill, mountain;" Skt. bhrant- "high;" O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg).

Niru, from Mid.Pers. nêrok, Av. nairya- "manly, male" (cf. Skt. nárya-), from nar- "man, male" (Mid./Mod.Pers. nar- "male," Skt. nár- "male").

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