AskDefine | Define accelerate

Dictionary Definition

accelerate

Verb

1 move faster; "The car accelerated" [syn: speed up, speed, quicken] [ant: decelerate]
2 cause to move faster; "He accelerated the car" [syn: speed, speed up] [ant: decelerate]

User Contributed Dictionary

English

Etymology

acceleratus, past participle of accelerare, formed from ad- + celerare "to hasten", which from celer "quick". See celerity.

Pronunciation

  • RP:
    • /əkˈsɛləˌreɪt/

Verb

  1. To cause to move faster; to quicken the motion of; to add to the speed of.
  2. To quicken the natural or ordinary progression or process of.
    to accelerate the growth of a plant, the increase of wealth, etc.
  3. To hasten, as the occurrence of an event.
    to accelerate our departure.
  4. To become faster; to begin to move more quickly.

Antonyms

Translations

to cause to move faster
to quicken natural or ordinary progression or process
to hasten
to become faster

Italian

Adjective

accelerate p

Verb

accelerate

Extensive Definition

In physics, acceleration is defined as the rate of change of velocity, or as the second derivative of position (with respect to time). It is then a vector quantity with dimension length/time². In SI units, acceleration is measured in meters/second² (m·s-2). The term "acceleration" generally refers to the rate of change in instantaneous velocity. (velocity is speed and direction)
In common speech, the term acceleration is only used for an increase in speed; a decrease in speed is called deceleration. In physics, any increase or decrease in speed is referred to as acceleration and similarly, motion in a circle at constant speed is also an acceleration, since the direction component of the velocity is changing. See also Newton's Laws of Motion.

Relation to relativity

After completing his theory of special relativity, Albert Einstein realized that forces felt by objects undergoing constant proper acceleration are indistinguishable from those in a gravitational field. This was the basis for his development of general relativity, a relativistic theory of gravity. This is also the basis for the popular Twin paradox, which asks why one twin ages less when moving away from his sibling at near light-speed and then returning, since the non-aging twin can say that it is the other twin that was moving. General relativity solved the "why does only one object feel accelerated?" problem which had plagued philosophers and scientists since Newton's time (and caused Newton to endorse absolute space). In special relativity, only inertial frames of reference (non-accelerated frames) can be used and are equivalent; general relativity considers all frames, even accelerated ones, to be equivalent. (The path from these considerations to the full theory of general relativity is traced in the Introduction to general relativity.)

Formula

The formula for the average acceleration over a time period \Delta t is
\mathbf=\frac
where
\mathbf(t+\Delta t) is the final velocity
\mathbf(t) is the initial velocity
\mathbf is the initial time and \Delta \mathbf is the change in time
The formula for the instantaneous acceleration at time t is
\mathbf(t)=\lim_\frac=\frac
Thus acceleration is the first derivative of velocity. One should note that the expression (Final position - Initial Position) / (Total time taken) is the average velocity, and the limit as the time interval approaches zero is the instantaneous velocity. Therefore, velocity is the first derivative of position, making acceleration the second.
One should also note that the average and instantaneous accelerations over a time period \Delta t=t_1-t_0 are related through the Mean Value Theorem for Integrals:
\bar\int_^\mathrmt=\int_^\mathbf(t)\mathrmt
Putting it all together means:
\mathbf = \frac = \frac
where
\mathbf is acceleration
\mathbf is velocity
\mathbf is position
is time
accelerate in Afrikaans: Versnelling
accelerate in Arabic: تسارع
accelerate in Asturian: Aceleración
accelerate in Bengali: ত্বরণ
accelerate in Min Nan: Ka-sok-tō͘
accelerate in Belarusian: Паскарэнне
accelerate in Bosnian: Ubrzanje
accelerate in Bulgarian: Ускорение
accelerate in Catalan: Acceleració
accelerate in Czech: Zrychlení
accelerate in Welsh: Cyflymiad
accelerate in Danish: Acceleration
accelerate in German: Beschleunigung
accelerate in Estonian: Kiirendus
accelerate in Modern Greek (1453-): Επιτάχυνση
accelerate in Spanish: Aceleración
accelerate in Esperanto: Akcelo
accelerate in Basque: Azelerazio
accelerate in Persian: شتاب
accelerate in French: Accélération
accelerate in Irish: Luasghéarú
accelerate in Manx: Bieauaghey
accelerate in Galician: Aceleración
accelerate in Hakka Chinese: Kâ-suk-thu
accelerate in Korean: 가속도
accelerate in Croatian: Ubrzanje
accelerate in Ido: Acelero
accelerate in Indonesian: Percepatan
accelerate in Icelandic: Hröðun
accelerate in Italian: Accelerazione
accelerate in Hebrew: תאוצה
accelerate in Latin: Acceleratio
accelerate in Latvian: Paātrinājums
accelerate in Lithuanian: Pagreitis
accelerate in Hungarian: Gyorsulás
accelerate in Malayalam: ത്വരണം
accelerate in Malay (macrolanguage): Pecutan
accelerate in Mongolian: Хурдатгал
accelerate in Dutch: Versnelling (natuurkunde)
accelerate in Japanese: 加速度
accelerate in Norwegian: Akselerasjon
accelerate in Norwegian Nynorsk: Akselerasjon
accelerate in Novial: Akseleratione
accelerate in Polish: Przyspieszenie
accelerate in Portuguese: Aceleração
accelerate in Quechua: P'ikwachiy
accelerate in Russian: Ускорение
accelerate in Sicilian: Accilirazzioni
accelerate in Simple English: Acceleration
accelerate in Slovak: Zrýchlenie
accelerate in Slovenian: Pospešek
accelerate in Serbian: Убрзање
accelerate in Serbo-Croatian: Ubrzanje
accelerate in Finnish: Kiihtyvyys
accelerate in Swedish: Acceleration
accelerate in Telugu: త్వరణము
accelerate in Thai: ความเร่ง
accelerate in Vietnamese: Gia tốc
accelerate in Turkish: İvme
accelerate in Ukrainian: Прискорення
accelerate in Chinese: 加速度

Synonyms, Antonyms and Related Words

activate, aggravate, atomize, beef up, blow up, bombard, bundle, bustle, cleave, complicate, concentrate, condense, consolidate, crack on, cross-bombard, crowd, deepen, dispatch, double, drive, drive on, enhance, exacerbate, exaggerate, expedite, fission, forward, gain ground, get going, haste, hasten, hasten on, heat up, heighten, hie on, hop up, hot up, hurry, hurry along, hurry on, hurry up, hustle, hustle up, impel, intensify, jazz up, key up, magnify, make complex, nucleize, open the throttle, pick up speed, precipitate, press, push, push on, push through, put on, put on steam, quicken, race, railroad through, ramify, redouble, reinforce, rev, rush, rush along, shake up, sharpen, smash the atom, soup up, speed, speed along, speed up, spur, stampede, step on it, step up, strengthen, triple, urge, whet, whip, whip along
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