/ak sel'euh ray"sheuhn/, n.
1. the act of accelerating; increase of speed or velocity.
2. a change in velocity.
3. Mech. the time rate of change of velocity with respect to magnitude or direction; the derivative of velocity with respect to time.
[1525-35; < L acceleration- (s. of acceleratio). See ACCELERATE, -ION]

* * *

Rate of change of velocity.

Acceleration, like velocity, is a vector quantity: it has both magnitude and direction. The velocity of an object moving on a straight path can change in magnitude only, so its acceleration is the rate of change of its speed. On a curved path, the velocity may or may not change in magnitude, but it will always change in direction, which means that the acceleration of an object moving on a curved path can never be zero. If velocity is stated in metres per second (m/s) and the time interval in seconds (s), then the units of acceleration are metres per second per second (m/s/s, or m/s2). See also centripetal acceleration.

* * *

      rate at which velocity changes with time, in terms of both speed and direction. A point or an object moving in a straight line is accelerated if it speeds up or slows down. Motion on a circle is accelerated even if the speed is constant, because the direction is continually changing. For all other kinds of motion, both effects contribute to the acceleration.

      Because acceleration has both a magnitude and a direction, it is a vector quantity. velocity is also a vector quantity. Acceleration is defined as the change in the velocity vector in a time interval, divided by the time interval. Instantaneous acceleration (at a precise moment and location) is given by the limit of the ratio of the change in velocity during a given time interval to the time interval as the time interval goes to zero (see analysis: Instantaneous rates of change (analysis)). For example, if velocity is expressed in metres per second, acceleration will be expressed in metres per second per second.

* * *

Universalium. 2010.


Look at other dictionaries:

  • accélération — [ akselerasjɔ̃ ] n. f. • 1327; lat. acceleratio, de accelerare 1 ♦ Cour. Augmentation de vitesse. L accélération d un mouvement. Cette voiture a des accélérations foudroyantes. Fig. Le fait d aller plus vite. L accélération du pouls, de la… …   Encyclopédie Universelle

  • Acceleration — Accélération L accélération désigne couramment une augmentation de la vitesse; en physique, plus précisément en cinématique, l accélération est une grandeur vectorielle qui indique la modification affectant la vitesse d un mouvement en fonction… …   Wikipédia en Français

  • acceleration — I noun dispatch, expedition, expeditious performance, hastening, hurrying, increase of speed, quickening, shortening of time, speedup, spurt, stepping up a pace associated concepts: acceleration clause, acceleration doctrine, acceleration of a… …   Law dictionary

  • Acceleration — Ac*cel er*a tion, n. [L. acceleratio: cf. F. acc[ e]l[ e]ration.] The act of accelerating, or the state of being accelerated; increase of motion or action; as, a falling body moves toward the earth with an acceleration of velocity; opposed to… …   The Collaborative International Dictionary of English

  • acceleration — of a point is the time rate of change of the velocity of the point. centripetal acceleration lateral acceleration longitudinal acceleration normal acceleration side acceleration vehicle acceleration …   Mechanics glossary

  • acceleration — The termination of the debtor s right to pay a debt in installments or at a future maturity date. If a debt is accelerated, the debt becomes immediately due and payable. Many contracts have acceleration clauses entitling the creditor to allow for …   Glossary of Bankruptcy

  • Acceleration — Acceleration, Beschleunigung, beschleunigende Kraft, die ein Körper auf die Bewegung eines andern ausübt. – 2. Acceleration des Mondes nennt die Astronomie die Beschleunigung des Mondlaufes um die Erde, in Folge deren dieser immer kürzer wird,… …   Herders Conversations-Lexikon

  • acceleration — Acceleration. subst. f. v. L action d accelerer. Il faut faire telle chose pour l acceleration de l ouvrage …   Dictionnaire de l'Académie française

  • Acceleration — (v. lat.), 1) Beschleunigung; bes. 2) Vermehrung der Geschwindigkeit; so: A. des Mondes, die immer größer werdende Geschwindigkeit des Mondes, od. die immer kürzere Umlaufszeit des Mondes um die Erde, s. u. Mond; A. der Fixsterne, Verfrühung der… …   Pierer's Universal-Lexikon

  • Acceleration — Acceleration, s. Beschleunigung …   Lexikon der gesamten Technik

  • acceleration — (n.) 1530s, from L. accelerationem (nom. acceleratio) a hastening, noun of action from pp. stem of accelerare (see ACCELERATE (Cf. accelerate)) …   Etymology dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.