acceleration (noun)

an increase in rate of change

"modern science caused an acceleration of cultural change"

acceleration, quickening, speedup (noun)

the act of accelerating; increasing the speed

acceleration (noun)

(physics) a rate of increase of velocity

acceleration (Noun)

The act of accelerating, or the state of being accelerated; increase of motion or action; as opposed to retardation or deceleration.

acceleration (Noun)

The amount by which a speed or velocity increases (and so a scalar quantity or a vector quantity).

acceleration (Noun)

The change of velocity with respect to time (can include deceleration or changing direction).

Acceleration

In physics, acceleration is the rate at which the velocity of a body changes with time. In general, velocity and acceleration are vector quantities, with magnitude and direction, though in many cases only magnitude is considered. As described by Newton's Second Law, acceleration is accompanied by a force; the force, as a vector, is the product of the mass of the object being accelerated and the acceleration. The SI unit of acceleration is the meter per second squared. For example, an object such as a car that starts from standstill, then travels in a straight line at increasing speed, is accelerating in the direction of travel. If the car changes direction at constant speedometer reading, there is strictly speaking an acceleration although it is often not so described; passengers in the car will experience a force pushing them back into their seats in linear acceleration, and a sideways force on changing direction. If the speed of the car decreases, it is usual and meaningful to speak of deceleration; mathematically it is acceleration in the opposite direction to that of motion.