1 Many instances of performance-based design are approved for their adherence to safety principles. 2  Ceremony implies honor, and honor implies an adherence to traditions. Many instances of performance-based design are approved for their adherence to safety principles. 2  Ceremony implies honor, and honor implies an adherence to traditions.
Acceleration is a vector quantity that is defined as the rate at which an object changes its velocity. An object is accelerating if it is changing its velocity. Sports announcers will occasionally say that a person is accelerating if he/she is moving fast. Yet acceleration has nothing to do with going fast.
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.