Acceleration is a vector quantity, meaning it has both magnitude and direction.
* Constant speed means the magnitude of the velocity (how fast the particle is moving) is unchanging.
* Acceleration refers to a change in velocity. This change can be a change in speed (magnitude) or a change in direction (or both).
Example:
* A car going around a circular track at a constant speed: The car's speed remains the same, but it's constantly changing direction. This change in direction means it has acceleration, even though its speed is constant.
Key takeaway:
* A particle can have constant speed and still be accelerating if its direction is changing.
* Only if both the speed and direction of a particle remain constant will its acceleration be zero.
