Here's why:
* Velocity has both speed and direction.
* Acceleration is the rate of change of velocity over time.
Therefore, when an object slows down, its velocity is changing (decreasing in speed) even though its direction might be constant. Since there's a change in velocity, it is considered an acceleration.
Key Points:
* Deceleration is simply acceleration in the opposite direction of the object's motion.
* Negative acceleration often indicates deceleration, but it's important to consider the context and direction.
* Zero acceleration means the object is moving at a constant speed in a straight line (no change in velocity).
Think of it this way:
* Accelerating means speeding up.
* Decelerating means slowing down.
* Both involve a change in velocity, which is the defining characteristic of acceleration.
