* Acceleration is a change in velocity. Velocity has two components: speed and direction.
* Constant speed means no change in speed. You are maintaining the same speed.
* Constant direction means no change in direction. You are moving in a straight line.
Since both speed and direction are constant, there is no change in velocity, meaning there is no acceleration.
Example: Driving a car at 60 mph due east is constant velocity. Even though you are moving, you are not accelerating because your speed and direction are not changing.
