noun

acceleration

ak-sel-uh-RAY-shun/əkˌseləˈreɪʃn/

The rate at which speed or direction of motion changes.

The widening gaps between the ball's successive positions reveal its acceleration.

One ball rolling down an incline shown at successive equal-time positions increasingly farther apart, accurate spacing conveys increasing speed, no labels/arrows.

Etymology

acLatinto, toward

+celerLatinswift

+ationLatinaction or process

The root meaning “swift” underlies a verb meaning “to hasten”; the noun names that process. Acceleration is therefore an increase in swiftness, rather than simply a high speed.

In context

The Organic Chemistry Tutor20:01

in 5 seconds so because the sports car can get to a higher speed or to a certain speed faster than the truck it has a greater acceleration

Physics - Basic Introduction

More examples

The instrument records changes in acceleration.
Turning changes a vehicle's velocity and therefore involves acceleration.
The engineer compares the accelerations produced by different forces.

Forms

acceleration · accelerations

Similar words

speed: Measures how fast something moves rather than change in velocity.
velocity: Describes speed and direction, not their rate of change.