Final answer:
Acceleration is a derived unit because it is the rate of change of velocity over time, resulting in the unit meters per second squared (m/s²). It represents how velocity changes in terms of speed per second and is a vector quantity, comprising both magnitude and direction.
Step-by-step explanation:
The unit of acceleration is considered a derived unit because it is composed of other basic units of measure. Specifically, acceleration is defined as the change in velocity (m/s) over a given period of time (s). Therefore, the SI units for acceleration are calculated as velocity divided by time, resulting in meters per second squared (m/s²). This dimensional analysis shows that acceleration signifies how many meters per second the velocity changes every second. Acceleration is a vector quantity because it has both a magnitude and a direction, and any change in the speed or direction of an object constitutes acceleration.
For example, if a car increases its speed from 0 to 60 m/s in 5 seconds, the acceleration is calculated as the change in velocity (60 m/s) divided by the time period (5 s), resulting in an acceleration of 12 m/s². Similarly, if the car decelerates to a stop in 5 seconds, the negative acceleration (deceleration) is also measured in m/s².