ancillae. 1  nominative plural of. 2  genitive singular of. 3  dative singular of.  vocative plural of.
Acceleration is the time rate of change of velocity. If velocity is constant, then. acceleration is zero. Note: 100 km per h for 10 seconds is a constant speed, but not necessarily a constant. velocity, since we're told nothing about the direction.
In physics or physical science, acceleration (symbol: a) is defined as the rate of change (or derivative with respect to time) of velocity. It is thus a vector quantity with dimension length/timeÂ². In SI units, acceleration is measured in meters/secondÂ² using an accelerometer. To accelerate an object is to change its velocity, which is accomplished by altering either its speed or direction (like in case of uniform circular motion) in relation to time.