acceleration

Everyday

1. Acceleration is getting faster: the speed going up. tree →
2. (science) Acceleration is how quickly speed (or velocity) changes; slowing down is a negative acceleration (deceleration). tree →
3. Acceleration is how quickly a car can speed up. tree →
4. Acceleration is also any speeding up of a process: the acceleration of climate change. tree →

In the lessons

Used in science lessons on forces and motion (Newton's laws, gravity makes falling objects accelerate), cars and sport (sprinters), and in maths (change of speed per second).

Examples

• The rocket's acceleration pushed the astronauts into their seats. tree →
• Gravity gives falling objects an acceleration. tree →
• This sports car has amazing acceleration. tree →
• The sprinter's acceleration out of the blocks won the race. tree →
• A bigger force gives a bigger acceleration. tree →
• On the graph, a steeper line shows greater acceleration. tree →
• Scientists worry about the acceleration of ice melting. tree →

Note

Verb: «accelerate». Double «c», one «l»: acceleration. In maths and science: acceleration = change in speed ÷ time. A car going from 0 to 20 metres per second in 4 seconds has an acceleration of 5 metres per second every second. Near Earth, falling objects accelerate at about 9.8 m/s². Constant speed means zero acceleration.