慣かん性せい系けい

noun

inertial frame of reference; inertial system

Physics term for a reference frame in which a body not subject to forces moves at constant velocity.

• ニュートンの第だい一いち法ほう則そくは慣かん性せい系けいでのみ成なり立たつ。

  Newton's first law holds only in inertial frames of reference.