How can velocity be defined?

Velocity is defined as the speed of an object in a specific direction. This means that velocity not only considers how fast an object is moving but also the directional component of that motion. For instance, if a car is traveling north at 60 kilometers per hour, its velocity would be described as 60 km/h north. This directional aspect is what distinguishes velocity from merely speed, which only quantifies how fast an object is moving without reference to direction.

The other options do refer to aspects related to movement, but they lack the critical directional component that defines velocity. Speed is a scalar quantity measuring the rate of motion, while linear speed and rotational speed describe movement along a straight path and around a circle, respectively, without incorporating direction. Hence, understanding velocity as speed in a given direction is fundamental in physics and engineering contexts, where the direction of motion can significantly impact analysis and outcomes.