If an object moves with constant acceleration, its velocity is changing at a constant rate. Here's why:

* Acceleration is the rate of change of velocity.

* Constant acceleration means the velocity changes by the same amount in every equal time interval.

Examples:

* A car accelerating from rest at a constant 5 m/s² will increase its velocity by 5 meters per second every second.

* A ball falling freely under gravity experiences a constant acceleration of 9.8 m/s². Its velocity increases by 9.8 meters per second every second.

Important Notes:

* Initial velocity matters: Even with constant acceleration, the object's velocity can be positive, negative, or zero depending on its initial velocity.

* Direction: Acceleration can change the magnitude and direction of velocity. For example, if an object accelerates in the opposite direction to its initial velocity, its speed will decrease.

Let me know if you'd like a more detailed explanation or specific examples!