* Velocity is a vector quantity that describes both the speed and direction of an object's motion.

* Speed is the rate at which an object moves, measured in units of distance per unit of time.

Common units for velocity:

* Meters per second (m/s): The standard unit in the International System of Units (SI).

* Kilometers per hour (km/h): Often used for road speeds.

* Miles per hour (mph): Commonly used in the United States.

Why the other options are incorrect:

* Newtons (N): Newtons are the unit of force, not velocity.

* Seconds (s): Seconds are units of time, not velocity.

Let me know if you have any other physics questions!