Which physical concept includes both the speed of an object and the direction of its motion?

Velocity is defined as a vector quantity that includes both the speed of an object and the direction in which the object is moving. In contrast to speed, which is a scalar quantity and only measures how fast an object is moving without any regard to the direction, velocity provides a complete description of the object's motion.

For example, if a car is traveling at 60 kilometers per hour to the north, its velocity is not just 60 kilometers per hour but specifically 60 kilometers per hour north. This distinction is crucial in physics as it influences how different objects interact and how their movements can be analyzed in various contexts, such as rivers and their flow rates.

The other concepts, such as acceleration, force, and mass, each represent different physical properties. Acceleration relates to the change in velocity over time, force pertains to the influence that causes an object to undergo a change in motion, and mass refers to the amount of matter in an object, none of which inherently include both speed and direction.