(がいりょく)

がいりょく
noun
external force; outside force
formalwrittenscience
1. external force; outside force
A force applied to an object or system from outside, as opposed to forces generated internally. Used in physics, engineering, and figuratively for outside pressure or influence.
It deforms when external force is applied.
The building is designed to withstand external forces such as earthquakes.
外力(がいりょく)なし変化(へんか)()きることない
Change does not occur without an external force.

Compound of (がい) ('outside; external') and (りょく) ('force; power'). A technical term from physics and engineering that also sees figurative use in social and political contexts.

Usage

  • In physics, corresponds to the English term 'external force' — a force acting on a body from outside the system being analyzed.
  • In structural engineering, 外力(がいりょく) includes forces like wind, earthquakes, and snow load that buildings must resist.
  • Figuratively, can describe political, economic, or social pressure from outside: 外力(がいりょく)による変革(へんかく) ('reform driven by outside forces').

Common collocations

Similar words

  • 内力(ないりょく): internal force — force generated within a system or body
  • 圧力(あつりょく): pressure — force per unit area; also used figuratively for political or social pressure
  • 重力(じゅうりょく): gravity — the specific external force due to gravitational attraction
  • 応力(おうりょく): stress (engineering) — the internal distribution of force within a material