Which statement best defines a vector quantity?

• A. A quantity that has both magnitude and direction
• B. A quantity with only magnitude
• C. A quantity with no direction
• D. A unit of measurement

Answer: (A)

Vector quantities are defined by having both magnitude and direction. This means you must specify not only how much, but also which way. For example, velocity describes how fast something is moving and in what direction, like 20 meters per second to the east. In contrast, scalar quantities have only magnitude and no direction, such as mass or temperature. A vector isn’t just a unit; it communicates both size and orientation, often represented graphically by an arrow where the length indicates magnitude and the arrow points in the direction.