What does inertia mean?
Word: Inertia
Part of Speech: Noun
Meaning: Inertia means in science, the way an object keeps still, or keeps moving in the same way, unless a force acts on it. In everyday use, it means a lazy feeling of not wanting to do anything.
Synonyms: inactivity, sluggishness, idleness
Antonyms: activity, energy, vigour
How do you spell inertia?
Syllables: in - er - tia
Tricky part: The 'sha' sound at the end is spelt -tia, not -sha or -cia. It comes from inert with ia added.
Watch out for: inersha, inercia, inertiya
Memory tip: Inert means not moving. Add ia and you have inertia, the habit of staying as you are.
Inertia in a sentence
Example 1: Inertia keeps a rolling football moving until the grass and the air slow it down.
Example 2: Rahul blamed inertia for the project he had been putting off for weeks.
Example 3: A heavy cupboard has more inertia, so it is harder to start pushing.
Fun Fact
Inertia comes from the Latin iners, meaning idle or without skill. The astronomer Johannes Kepler was one of the first to use it for the way objects resist a change in motion.
Practise the CREST Way
Jumble Tumble
Choose the correct sequence of the jumbled letters to form a meaningful word:
AIENRTI 1234567
a) 2347651
b) 2346571
c) 7432651
d) 2435671
Show answer
d) 2435671. Begin with I (2), N (4) and E (3); then R, T, the second I and A at the end.
Word Puzzle
Match the words with their meanings:
1. inertia 2. friction 3. gravity a. the force that slows down surfaces rubbing together b. the force that pulls things towards the Earth c. the reason a still object stays put until something pushes it
a) 1-c, 2-b, 3-a
b) 1-c, 2-a, 3-b
c) 1-a, 2-c, 3-b
d) 1-b, 2-c, 3-a
Show answer
b) 1-c, 2-a, 3-b. Inertia is about staying as you are, friction is about rubbing and gravity is about the pull of the Earth.
Spell Probe
Which option gives the meaning of the misspelt word in the sentence?
Our teacher showed us inertia by flicking a card from under a coin, and we wrote up the experiment in our science laboratery notebook.
a) a small piece of stiff paper
b) a test done to find out or show something
c) a room used for scientific work and tests
d) a flat round piece of metal used as money
Show answer
c) a room used for scientific work and tests. Laboratory is the misspelt word; it ends in -tory, and it names a room for science work.
Word Champ
Choose the correct word for the blank:
After the long holidays, a feeling of ________ made it hard for me to get back to my homework.
a) inertia
b) ambition
c) curiosity
d) urgency
Show answer
a) inertia. Ambition, curiosity and urgency all push you to act; inertia is the heavy feeling of not wanting to start.
Multiple Choice Questions
1. When a bus brakes suddenly, why do standing passengers lurch forward?
a) The floor pushes them forward.
b) The wind blows them forward.
c) Gravity pulls them forward.
d) Their bodies tend to keep moving.
Show answer
d) Their bodies tend to keep moving.
2. Which scientist's first law of motion is often called the law of inertia?
a) C V Raman
b) Marie Curie
c) Charles Darwin
d) Isaac Newton
Show answer
d) Isaac Newton
