Meaning & use
inertia
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Meanings
noununcountablephysics
The tendency of a physical object to stay still or keep moving in a straight line unless a force acts on it.
Grammar: Uncountable; no plural in scientific use.
Patterns
- because of inertia
- due to inertia
- the law of inertia
Because of inertia, your coffee keeps moving forward when the car brakes.
A ball rolls for a long time on smooth ice because of inertia.
Newton's first law of motion is sometimes called the law of inertia.
noununcountablefigurative
A tendency to do nothing or to keep things unchanged; resistance to taking action.
Grammar: Uncountable; often modified by bureaucratic, political, or sheer.
Patterns
- bureaucratic inertia
- overcome inertia
- sheer inertia
- political inertia
Bureaucratic inertia kept the project frozen for years.
The company finally overcame its inertia and moved its services online.
Out of sheer inertia, the committee kept the weekly meeting that nobody needed.
Common combinations
- overcome inertia
- A clear deadline helped the team overcome its inertia.
- bureaucratic inertia
- Bureaucratic inertia delayed the road repairs for years.
- sheer inertia
- Out of sheer inertia, the old rule was never changed.
- due to inertia
- The boxes slid forward due to inertia when the van stopped.
Synonyms and how they differ
- inactivity
- A neutral state of doing nothing; it lacks the idea of a force or habit that resists change.
- stagnation
- No growth or development, often economic; stronger and more negative than inertia.
- idleness
- Not working or being used; usually said about people or machines, not organizations or systems.
Opposites
Word family
- inert adjective
- Unable to move or act; in chemistry, not reacting with other substances.
Commonly confused: inertia or inert?
inertia vs inert
Inert is the adjective meaning unable to move or chemically unreactive; inertia is the noun for the tendency itself.
Practice
Passengers jerk forward when a bus stops suddenly because of ___.
Choose one answer.
Inertia is the tendency of a moving body to keep moving, which carries the passengers forward when the bus stops. Momentum is tempting but names the quantity of motion, not the tendency; friction opposes sliding, and gravity pulls downward, so neither explains the forward lurch.
Make it your own
Write a sentence using “inertia”, then check it and compare it with the examples above.