Which of the following is an example of a Vector Quality?

• A. Velocity
• B. Speed
• C. Distance
• D. Time

Answer: (A)

A vector quantity is something that has both a magnitude (how much) and a direction. Velocity fits this definition because it tells you how fast something is moving and in which direction. In contrast, speed only describes how fast, with no direction, so it is a scalar. Distance measures how much ground is covered without regard to direction, also a scalar. Time is simply a duration, not related to motion’s rate or direction, so it is scalar too. For example, a car moving 60 km/h to the east has a velocity of 60 km/h east, which conveys both the rate and the direction of motion. The same motion described only by speed would be 60 km/h, missing where it’s headed.