Editing Force (section)

{{Short description|Influence that can change motion of an object}}
{{Redirect|Physical force||Force (disambiguation)|and|Physical force (disambiguation)}}
{{Infobox physical quantity
| name = Force
| width =
| background =
| image = [[File:Force examples.svg|200px]]
| caption = Forces can be described as a push or pull on an object. They can be due to phenomena such as [[gravity]], [[magnetism]], or anything that might cause a mass to accelerate.
| unit = [[newton (unit)|newton]] (N)
| otherunits = [[dyne]], [[pound-force]], [[poundal]], [[kip (unit)|kip]], [[kilopond]]
| symbols = <math>\vec F</math>, {{mvar|F}}, {{math|'''F'''}}
| baseunits = [[kilogram|kg]]·[[metre|m]]·[[second|s]]<sup>−2</sup>
| dimension = wikidata
| derivations = {{math|1='''F''' = ''[[Mass|m]]''[[Acceleration|'''a''']]}}
}}
{{Classical mechanics|expanded=Fundamental concepts}}

In [[physics]], a '''force''' is an influence that can cause an [[Physical object|object]] to change its [[velocity]] unless counterbalanced by other forces. In mechanics, force makes ideas like ''''pushing'''' or ''''pulling'''' mathematically precise. Because the [[Magnitude (mathematics)|magnitude]] and [[Direction (geometry, geography)|direction]] of a force are both important, force is a [[Euclidean vector|vector]] quantity. The [[SI unit]] of force is the [[newton (unit)|newton (N)]], and force is often represented by the symbol {{math|'''F'''}}.

Force plays an important role in classical mechanics. The concept of force is central to all three of [[Newton's laws of motion]]. Types of forces often encountered in [[classical mechanics]] include [[Elasticity (physics)|elastic]], [[friction]]al, [[Normal force|contact or "normal" forces]], and [[gravity|gravitational]]. The rotational version of force is [[torque]], which produces [[angular acceleration|changes in the rotational speed]] of an object. In an extended body, each part applies forces on the adjacent parts; the distribution of such forces through the body is the internal [[stress (mechanics)|mechanical stress]]. In the case of multiple forces, if the net force on an extended body is zero the body is in equilibrium.

In [[modern physics]], which includes [[Theory of relativity|relativity]] and [[quantum mechanics]], the laws governing motion are revised to rely on [[fundamental interactions]] as the ultimate origin of force. However, the understanding of force provided by classical mechanics is useful for practical purposes.<ref>{{Cite web |last=Cohen |first=Michael |title=Classical Mechanics: a Critical Introduction |url=https://www.physics.upenn.edu/sites/default/files/Classical_Mechanics_a_Critical_Introduction_0_0.pdf |url-status=live |archive-url=https://web.archive.org/web/20220703194458/https://www.physics.upenn.edu/sites/default/files/Classical_Mechanics_a_Critical_Introduction_0_0.pdf |archive-date=July 3, 2022 |access-date=January 9, 2024 |website=[[University of Pennsylvania]]}}</ref>