Speed in a certain direction or the rate of change of the position of an object.

For motion in one dimension, such as along the number line, velocity is a scalar and for motion in two dimensions or through three-dimensional space, velocity is a vector.

The rate at which a moving car changes its position when traveling in a given direction: If a car goes around a corner without changing speed, its velocity changes because the car changes direction.

The minimum speed with which an object must be projected for it to break free from the gravitational pull of a planetary body: The escape velocity describes the effective separation from the gravitational field of a star, planet, or other celestial body.

A projectile must have a minimal velocity which has been worked out in a special formula.