Final answer:
Velocity is the vector quantity that provides both the speed and direction of an object's movement, distinguishing it from scalar speed which lacks directional information. Average velocity is calculated by dividing displacement by time, while instantaneous velocity reflects motion at a specific moment.
Step-by-step explanation:
The velocity of an object is a vector quantity that describes both how fast an object moves (its speed) and in what direction it moves. Unlike speed, which is a scalar quantity considering only the magnitude of motion, velocity encapsulates the direction, making it a more comprehensive measure of motion. Average velocity is determined by dividing the displacement, which is a vector that represents the change in position, by the time during which the displacement occurs. It's important to distinguish between instantaneous velocity, which is the velocity at a specific instant, and average velocity, which is calculated over a period of time.
When we talk about an object's motion in physics, answering questions about speed is different from answering questions about velocity. For instance, if an object moves 20 kilometers in an hour due south, this is a description of velocity. If it just moves 20 kilometers in an hour without a specified direction, that's just speed.
By understanding these distinctions between speed and velocity, it becomes clear that velocity involves both quantitative and directional information about an object's motion, making it a fundamental concept in physics studies.