centrifugal force
 離心力
 Cen·trip·e·tal a.
 1. Tending, or causing, to approach the center.
 2. Bot. (a) Expanding first at the base of the inflorescence, and proceeding in order towards the summit. (b) Having the radicle turned toward the axis of the fruit, as some embryos.
 3. Progressing by changes from the exterior of a thing toward its center; as, the centripetal calcification of a bone.
 Centripetal force Mech., a force whose direction is towards a center, as in case of a planet revolving round the sun, the center of the system, See Centrifugal force, under Centrifugal.
 Centripetal impression Physiol., an impression (sensory) transmitted by an afferent nerve from the exterior of the body inwards, to the central organ.
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 Cen·trif·u·gal a.
 1. Tending, or causing, to recede from the center.
 2. Bot. (a) Expanding first at the summit, and later at the base, as a flower cluster. (b) Having the radicle turned toward the sides of the fruit, as some embryos.
 Centrifugal force Mech., a force whose direction is from a center.
 Note: ☞ When a body moves in a circle with uniform velocity, a force must act on the body to keep it in the circle without change of velocity. The direction of this force is towards the center of the circle. If this force is applied by means of a string to the body, the string will be in a state of tension. To a person holding the other end of the string, this tension will appear to be directed toward the body as if the body had a tendency to move away from the center of the circle which it is describing. Hence this latter force is often called centrifugal force. The force which really acts on the body being directed towards the center of the circle is called centripetal force, and in some popular treatises the centripetal and centrifugal forces are described as opposing and balancing each other. But they are merely the different aspects of the same stress.
 Centrifugal impression Physiol., an impression (motor) sent from a nerve center outwards to a muscle or muscles by which motion is produced.
 Centrifugal machine, A machine for expelling water or other fluids from moist substances, or for separating liquids of different densities by centrifugal action; a whirling table.
 Centrifugal pump, a machine in which water or other fluid is lifted and discharged through a pipe by the energy imparted by a wheel or blades revolving in a fixed case. Some of the largest and most powerful pumps are of this kind.
 Force, n.
 1. Capacity of exercising an influence or producing an effect; strength or energy of body or mind; active power; vigor; might; often, an unusual degree of strength or energy; especially, power to persuade, or convince, or impose obligation; pertinency; validity; special signification; as, the force of an appeal, an argument, a contract, or a term.
    He was, in the full force of the words, a good man.   --Macaulay.
 2. Power exerted against will or consent; compulsory power; violence; coercion; as, by force of arms; to take by force.
    Which now they hold by force, and not by right.   --Shak.
 3. Strength or power for war; hence, a body of land or naval combatants, with their appurtenances, ready for action; -- an armament; troops; warlike array; -- often in the plural; hence, a body of men prepared for action in other ways; as, the laboring force of a plantation; the armed forces.
    Is Lucius general of the forces?   --Shak.
 4. Law (a) Strength or power exercised without law, or contrary to law, upon persons or things; violence. (b) Validity; efficacy.
 5. Physics Any action between two bodies which changes, or tends to change, their relative condition as to rest or motion; or, more generally, which changes, or tends to change, any physical relation between them, whether mechanical, thermal, chemical, electrical, magnetic, or of any other kind; as, the force of gravity; cohesive force; centrifugal force.
 Animal force Physiol., muscular force or energy.
 Catabiotic force [Gr. ░ down (intens.) + ░ life.] Biol., the influence exerted by living structures on adjoining cells, by which the latter are developed in harmony with the primary structures.
 Centrifugal force, Centripetal force, Coercive force, etc. See under Centrifugal, Centripetal, etc.
 Composition of forces, Correlation of forces, etc. See under Composition, Correlation, etc.
 Force and arms [trans. of L. vi et armis] Law, an expression in old indictments, signifying violence.
 In force, or Of force, of unimpaired efficacy; valid; of full virtue; not suspended or reversed. “A testament is of force after men are dead.” --Heb. ix. 17.
 Metabolic force Physiol., the influence which causes and controls the metabolism of the body.
 No force, no matter of urgency or consequence; no account; hence, to do no force, to make no account of; not to heed. [Obs.] --Chaucer.
 Of force, of necessity; unavoidably; imperatively. “Good reasons must, of force, give place to better.” --Shak.
 Plastic force Physiol., the force which presumably acts in the growth and repair of the tissues.
 Vital force Physiol., that force or power which is inherent in organization; that form of energy which is the cause of the vital phenomena of the body, as distinguished from the physical forces generally known.
 Syn: -- Strength; vigor; might; energy; stress; vehemence; violence; compulsion; coaction; constraint; coercion.
 Usage: Force, Strength. Strength looks rather to power as an inward capability or energy. Thus we speak of the strength of timber, bodily strength, mental strength, strength of emotion, etc. Force, on the other hand, looks more to the outward; as, the force of gravitation, force of circumstances, force of habit, etc. We do, indeed, speak of strength of will and force of will; but even here the former may lean toward the internal tenacity of purpose, and the latter toward the outward expression of it in action. But, though the two words do in a few cases touch thus closely on each other, there is, on the whole, a marked distinction in our use of force and strength. “Force is the name given, in mechanical science, to whatever produces, or can produce, motion.”
 Thy tears are of no force to mollify
 This flinty man.   --Heywood.
    More huge in strength than wise in works he was.   --Spenser.
 Adam and first matron Eve
 Had ended now their orisons, and found
 Strength added from above, new hope to spring
 Out of despair.   --Milton.
 centrifugal force
      n : the outward force on a body moving in a curved path around
          another body [ant: centripetal force]