# velocity

velocity
Rate of movement; specifically, distance traveled or quantity converted per unit time in a given direction. Cf.:speed. [L. velocitas, fr. velox (veloc-), quick, swift]
- initial v. the rate of a reaction, e.g., an enzyme-catalyzed reaction, at the early stages of the reaction such that the product(s) concentrations have not risen to a level to significantly affect the observable rate; typically, initial velocities are observed when less than 10% of the reaction's approach toward equilibrium has occurred. SYN: initial rate.
- maximum v. (Vmax) 1. the maximum rate of an enzyme-catalyzed reaction that can be achieved by progressively increasing the substrate concentration at a given enzyme concentration; in cases of substrate inhibition, Vmax is an extrapolated value in the absence of such inhibition; Cf.:Michaelis-Menten equation. 2. the maximum initial rate of shortening of a myocardial fiber that can be obtained under zero load; used to evaluate the contractility of the fiber.
- nerve conduction v. the rate of impulse conduction in a peripheral nerve or its various component fibers, generally expressed in meters per second.
- PSA v. a measure of the rapidity of change in a person's PSA level.
- sedimentation v. the rate of movement of a substance, typically a macromolecule, in centrifugation; these centrifugation studies provide data on the structure of the macromolecule.
- steady-state v. the v. of an enzyme-catalyzed reaction in which, over the time course of the study, the concentration of any enzyme species is constant ( i.e., for an enzyme-substrate binary complex, ES, d[ES]/dt ≈ 0; for this to hold true, the total enzyme concentration must be much less than the initial substrate concentration. SYN: steady-state rate.

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(v) ve·loc·i·ty (v) (və-losґĭ-te) [L. velox swift] the rate of movement of a body in a given direction.

Medical dictionary. 2011.

Synonyms:

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• Velocity — Ve*loc i*ty, n.; pl. {Velocities}. [L. velocitas, from velox, ocis, swift, quick; perhaps akin to v?lare to fly (see {Volatile}): cf. F. v[ e]locit[ e].] [1913 Webster] 1. Quickness of motion; swiftness; speed; celerity; rapidity; as, the… …   The Collaborative International Dictionary of English

• Velocity — (dt. Geschwindigkeit) bezeichnet bei anschlagsdynamischen elektronischen Tasteninstrumenten (z. B. Synthesizer oder Keyboards) die sogenannte Anschlagsgeschwindigkeit, d. h. diejenige Geschwindigkeit, mit der eine Taste niedergedrückt… …   Deutsch Wikipedia

• velocity — index haste, rate Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

• velocity — 1550a, from L. velocitatem (nom. velocitas) swiftness, speed, from velox (gen. velocis) swift, of uncertain origin, perhaps related to vehere carry (see VEHICLE (Cf. vehicle)), or from the same root as vegetable (see VIGIL (Cf. vigil)) …   Etymology dictionary

• velocity — *speed, momentum, impetus, pace, headway Analogous words: *celerity, legerity, alacrity: *haste, hurry, expedition, dispatch …   New Dictionary of Synonyms

• velocity — [n] speed acceleration, celerity, dispatch, expedition, fleetness, gait, haste, headway, hurry, impetus, momentum, pace, quickness, rapidity, rapidness, rate, swiftness, tempo; concepts 755,792 …   New thesaurus

• velocity — ► NOUN (pl. velocities) 1) the speed of something in a given direction. 2) (in general use) speed. ORIGIN Latin velocitas, from velox swift …   English terms dictionary

• velocity — [və läs′ə tē] n. pl. velocities [Fr vélocité < L velocitas < velox: see VELOCIPEDE] 1. quickness or rapidity of motion or action; swiftness; speed 2. a) rate of change of position, in relation to time; SPEED (sense 2a) b) …   English World dictionary

• Velocity — In physics, velocity is defined as the rate of change of position. It is a vector physical quantity; both speed and direction are required to define it. In the SI (metric) system, it is measured in meters per second: (m/s) or ms 1. The scalar… …   Wikipedia

• velocity — 1) a vector quantity equal to the rate that position changes with time 2) velocity of a point in a vibrating system is the time rate of change of its displacement. ambient wind velocity forward velocity impact velocity lateral velocity… …   Mechanics glossary

• Velocity XL — The Velocity XL is the eXtra Large version of the canard pusher aircraft from Velocity Aircraft. Available in 4 seat or 5 seat (the 5 version) configurations, this aircraft offers spacious, high performance long distance stylish cruising. Powered …   Wikipedia