What does decelerate mean?
Word: Decelerate
Part of Speech: Verb
Meaning: Decelerate means to reduce speed; to go more slowly.
Synonyms: slow down
How do you spell decelerate?
Syllables: de - cel - er - ate
Tricky part: The s sound after de is spelt with a c, not an s: deselerate is the slip to avoid.
Watch out for: deselerate, decelerrate
Memory tip: Think of a car easing off at a busy city crossing: city and decelerate both use c for that s sound.
Decelerate in a sentence
Example 1: The bus decelerated smoothly at the school gate.
Example 2: Our physics teacher showed us a graph of a ball decelerating as it rolled uphill.
Example 3: After landing, planes decelerate using their brakes and by reversing the thrust of their engines.
Fun Fact
Space capsules returning to Earth use the drag of the air, and then parachutes, to decelerate from thousands of kilometres an hour.
Practise the CREST Way
Word Cookie
Insert the correct pair of letters to form a word:
dec_l_rate
a) i, e
b) a, e
c) e, a
d) e, e
Show answer
d) e, e. Both missing letters are e: said slowly, each of those vowels is a short e sound.
Word Cookie
Find the extra letter in the word:
decellerate
a) l
b) c
c) r
d) e
Show answer
a) l. Only one l is needed; a double l would not change the sound.
Word Connection
Choose the antonym of the word decelerate as used in the sentence:
The train began to decelerate as it neared Howrah station.
a) stop
b) idle
c) brake
d) accelerate
Show answer
d) accelerate. To accelerate is to speed up, the opposite of slowing; braking and stopping go with decelerating.
Spell-o-Spell
Only one word in the list is misspelt. Choose the meaning of that word.
1. decelerate 2. friction 3. momentem 4. velocity
a) speed in a given direction
b) the force that resists one surface sliding over another
c) the quantity of motion a moving object has
d) to reduce speed
Show answer
c) the quantity of motion a moving object has. Momentum ends in um; decelerate, velocity and friction are correct.
Multiple Choice Questions
1. A cyclist who decelerates before a sharp bend is ____.
a) reducing speed to take the turn safely
b) pedalling harder to get round faster
c) ringing her bell to warn walkers
d) moving across to another lane
Show answer
a) reducing speed to take the turn safely
2. When its engine is switched off, what makes a moving boat decelerate?
a) water pushing against the hull
b) the extra fuel left in its tank
c) a strong wind blowing from behind
d) the warmth of the sun on the deck
Show answer
a) water pushing against the hull
