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Physics vocabulary · Motion and Forces

Inertia

Meaning in physics, with examples

/ɪˈnɜːrʃə/nounCore term

In physics, inertia means: The tendency of an object to resist any change in its motion, so it stays at rest or keeps moving with the same velocity. Objects with more mass have more inertia.

In Turkish: eylemsizlik, atalet

How it is used

Linked to Newton's first law, which is sometimes called the law of inertia. Used when explaining seat belts, the tablecloth trick or why heavy trucks need longer to stop. For rotation, physicists use 'moment of inertia'.

Example sentences

  1. Because of inertia, your body keeps moving forward when the car stops suddenly.

  2. A loaded truck has more inertia than an empty one, so it is harder to stop.

Common collocations

  • law of inertia
  • moment of inertia
  • inertial frame of reference
  • massThe amount of matter in an object, which also measures how hard it is to change the object's motion. It is measured in kilograms (kg) and does not depend on location.
  • Newton's laws of motionThree basic laws that describe how forces affect motion: an object keeps its state of motion unless a net force acts, net force equals mass times acceleration, and every action has an equal and opposite reaction.
  • momentumThe product of an object's mass and its velocity (p = mv). It is a vector and is measured in kilogram metres per second (kg·m/s).
  • forceA push or a pull that can change how an object moves or change its shape. It has both size and direction and is measured in newtons (N).

More terms: Motion and Forces

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