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.
Acceleration is a vector when it refers to the rate of change of velocity. Acceleration is scalar when it refers to rate of change of speed. A car slowing down to stop at a stop sign is accelerating because its speed is changing. We might refer to this type of acceleration as deceleration or negative acceleration.