* Velocity: Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.
* Acceleration: Acceleration is the rate of change of velocity. This means that acceleration occurs when either the speed or the direction of the velocity changes.
Therefore, if a particle's velocity is constant, both its speed and direction are unchanging. Since there is no change in velocity, there is no acceleration.
Example: A car traveling at a steady 60 mph in a straight line has constant velocity. It is not accelerating, even though it is moving.
