* Velocity: Velocity is a measure of both speed and direction. If an object is stationary, its velocity is zero.
* Acceleration: Acceleration is the rate of change of velocity. It means that even if an object is currently at rest (zero velocity), if its velocity is about to change, it is accelerating.
Examples:
* A ball at the top of its trajectory: A ball thrown straight up in the air momentarily stops at its highest point before falling back down. At this point, its velocity is zero, but it's still accelerating due to gravity.
* A car at a red light: A car stopped at a red light has a velocity of zero. However, when the light turns green, the car starts to move, indicating it was accelerating even while stopped.
Key Concept: Acceleration is about *change* in velocity, not just the velocity itself.
