* Acceleration is the rate of change of velocity. This means acceleration happens when the speed or direction of an object changes.
* Constant velocity means both speed and direction are unchanging. If neither speed nor direction is changing, the velocity isn't changing, and therefore there is no acceleration.
Examples:
* A car driving down a straight road at a steady 60 mph. The car is moving, but its speed and direction are not changing, so it has zero acceleration.
* A ball rolling across a frictionless surface at a constant speed. Even though the ball is in motion, it's not speeding up or slowing down, and it's not changing direction.
Key Takeaway:
Zero acceleration doesn't mean the object is at rest; it means the object is moving at a constant speed in a constant direction.
