Definition

1. Noun:
   • (Physics) The tendency of a body to maintain its state of rest or uniform motion in a straight line unless acted upon by an external force. This is a fundamental property of matter described by Newton's first law of motion.
   • A tendency to do nothing or to remain unchanged; a lack of activity or movement. This figurative sense describes a psychological or behavioral resistance to change or action.

Usage and Examples

• Physics Context:

  • The inertia of the large ship made it difficult to stop quickly.
  • An object in space will continue moving due to inertia unless a force slows it down.

• Figurative/Behavioral Context:

  • Bureaucratic inertia often delays important projects.
  • She felt a sense of inertia after the long holiday and struggled to start working.

Advanced Usage

• "Moment of inertia": (Physics) A measure of a body's resistance to angular acceleration about a given axis. It depends on the mass distribution relative to the axis.

  • The moment of inertia of a flywheel allows it to store rotational energy.

• "Overcome inertia": To force oneself or something to start moving or changing after a period of inactivity.

  • The new manager's energy helped the team overcome its inertia.

• "Inertia selling": (Commerce) The unethical practice of sending unrequested goods to a person and then demanding payment.

  • Be wary of inertia selling schemes.

Variants and Related Words

• Inert (adj): Lacking the ability or strength to move; or chemically inactive.

  • The patient lay inert on the bed.
  • Helium is an inert gas.

• Inertial (adj): Relating to or arising from inertia.

  • The spacecraft uses inertial guidance systems.

Synonyms

• Physics: Inactivity (in a specific scientific sense), momentum (when in motion).
• Figurative: Apathy, lethargy, inactivity, stagnation, torpor, idleness.

Antonyms

• Physics: Responsiveness.
• Figurative: Activity, energy, movement, action, liveliness.

Related Idioms and Phrases

• "Force of inertia": Often used to emphasize the powerful, passive resistance to change.

  • The force of institutional inertia prevented the adoption of new methods.

• "Succumb to inertia": To give in to the feeling of not wanting to act or move.

  • On rainy Sundays, I often succumb to inertia and stay in bed all day.

Noun

1. (physics) the tendency of a body to maintain its state of rest or uniform motion unless acted upon by an external force
2. a disposition to remain inactive or inert
   • he had to overcome his inertia and get back to work