* Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.
* Speed is a scalar quantity, meaning it only has magnitude.
Examples:
* Constant speed, changing velocity: A car driving in a circle at a constant speed has a changing velocity because its direction is constantly changing.
* Changing speed, changing velocity: A car accelerating in a straight line has a changing velocity because both its speed and direction are changing.
In conclusion:
A change in velocity *always* indicates a change in either speed, direction, or both. However, a change in speed only indicates a change in velocity if the direction remains constant.
