Average acceleration, , is the rate of change of an object's velocity per unit time. It is a vector quantity with units
- If an object is speeding up it experiences a positive acceleration.
- If an object is slowing down it experiences negative acceleration or deceleration.
- If an object is traveling at a constant velocity it has an acceleration of zero.
We have just discussed average acceleration; however, it is also important to understand instantaneous and constant acceleration.
Instantaneous acceleration is the acceleration of an object at a specific time.
Constant acceleration occurs when the object's velocity changes by equal amounts in equal periods of time. It is an example of uniform motion.