acceleration
rate at which the magnitude and/or direction of velocity changes with time
proper acceleration
physical acceleration experienced by an object
acceleration of free fall
at a point on Earth, vector sum of gravitational and centrifugal acceleration
gravitational acceleration
acceleration of an object caused by gravity
Peak ground acceleration
maximum ground acceleration during an earthquake at a location
tidal acceleration
cause of tidal locking
sound particle acceleration
instantaneous acceleration of a sound particle
deceleration
acceleration contrary to an object's direction of motion, slowing it down