Acceleration

[[Image:DonPrudhommeFire1991KennyBernstein.jpg|thumb|upright=1.4|[[Drag racing]] is a sport in which specially-built vehicles compete to be the fastest to accelerate from a standing start.]]

[[Image:DonPrudhommeFire1991KennyBernstein.jpg|thumb|upright=1.4|[[Drag racing]] is a sport in which specially-built vehicles compete to be the fastest to accelerate from a standing start.]]

In [[kinematics]], '''acceleration''' is the [[time derivative]] of [[velocity]]. Since velocity is a [[vector quantity]], so is acceleration.{{cite book |title=Relativity and Common Sense |first=Hermann |last=Bondi |pages=[https://archive.org/details/relativitycommon0000bond/page/3 3] |publisher=Courier Dover Publications |year=1980 |isbn=978-0-486-24021-3 |url=https://archive.org/details/relativitycommon0000bond/page/3 }}{{cite book |title=Physics the Easy Way |pages=[https://archive.org/details/physicseasyway00lehr_0/page/27 27] |first=Robert L. |last=Lehrman |publisher=Barron's Educational Series |year=1998 |isbn=978-0-7641-0236-3 |url=https://archive.org/details/physicseasyway00lehr_0/page/27 }}. The [[International System of Units|SI]] unit for acceleration is [[metre per second squared]] ({{nowrap|m⋅s⁻²}}, {{nowrap|m/s²}}).

In [[physics]], '''acceleration''' is what occurs when a body changes [[speed]] or its motion changes [[direction (geometry)|direction]]. Acceleration is a part of the study of [[motion]] and is one of several components of [[kinematics]]. It is defined as the [[time derivative|rate of change]] of the [[velocity]]. Like velocity, acceleration has a [[magnitude (mathematics)|magnitude]] and a [[direction (geometry)|direction]], making it a [[vector quantity]].{{cite book |title=Relativity and Common Sense |first=Hermann |last=Bondi |pages=[https://archive.org/details/relativitycommon0000bond/page/3 3] |publisher=Courier Dover Publications |year=1980 |isbn=978-0-486-24021-3 |url=https://archive.org/details/relativitycommon0000bond/page/3 }}{{cite book |title=Physics the Easy Way |pages=[https://archive.org/details/physicseasyway00lehr_0/page/27 27] |first=Robert L. |last=Lehrman |publisher=Barron's Educational Series |year=1998 |isbn=978-0-7641-0236-3 |url=https://archive.org/details/physicseasyway00lehr_0/page/27 }}.

The '''tangential acceleration''' of an object is the component of the '''acceleration''' which is in the same direction as the motion (or [[tangential velocity]]) of the object. When the velocity of the object does not change direction, this is called '''linear acceleration'''. '''Deceleration''' or '''retardation''', on the other hand, is the component of the acceleration in the opposite (or [[Antiparallel vector|antiparallel]]) direction to the tangential velocity. '''Radial acceleration''' or '''normal acceleration''' (or '''centripetal acceleration''' during circular motions) is the component of the acceleration that changes the direction of the object's velocity.

The '''tangential acceleration''' of an object is the component of the '''acceleration''' which is in the same direction as the motion (or [[tangential velocity]]) of the object. When the velocity of the object does not change direction, this is called '''linear acceleration'''. '''Deceleration''' or '''retardation''', on the other hand, is the component of the acceleration in the opposite (or [[Antiparallel vector|antiparallel]]) direction to the tangential velocity. '''Radial acceleration''' or '''normal acceleration''' (or '''centripetal acceleration''' during circular motions) is the component of the acceleration that changes the direction of the object's velocity.

In [[Newtonian mechanics]], the acceleration of a [[mass]] arises from [[forces]] acting on it, with its ''net'' acceleration being a result of the ''net'' force acting on it. By [[Newton's second law]],{{cite book |title=The Principles of Mechanics |first=Henry |last=Crew |publisher=BiblioBazaar, LLC |year=2008 |isbn=978-0-559-36871-4 |page=43}} the magnitude of the ''net'' acceleration will be [[Proportionality (mathematics)|proportional]] to the magnitude of the ''net'' force acting on the object and inversely proportional to the mass of the object, while the direction of the ''net'' acceleration will be the same as the direction of the ''net'' force.

In [[Newtonian mechanics]], the acceleration of a [[mass]] arises from [[forces]] acting on it, with its ''net'' acceleration being a result of the ''net'' force acting on it. By [[Newton's second law]],{{cite book |title=The Principles of Mechanics |first=Henry |last=Crew |publisher=BiblioBazaar, LLC |year=2008 |isbn=978-0-559-36871-4 |page=43}} the magnitude of the ''net'' acceleration will be [[Proportionality (mathematics)|proportional]] to the magnitude of the ''net'' force acting on the object and inversely proportional to the mass of the object, while the direction of the ''net'' acceleration will be the same as the direction of the ''net'' force.

The [[International System of Units|SI]] unit for acceleration is [[metre per second squared]] ({{nowrap|m⋅s⁻²}}, {{nowrap|m/s²}}).

== Definition and properties ==

== Definition and properties ==