Q. What is the difference between speed and velocity?
A. Speed is a change in distance divided by a change in time. Velocity is a special type of speed, it is speed in a particular (straight line) direction. Speed is represented by a single number. Velocity is described with two terms, a number (the speed), and the direction the body is moving. Velocity is typically described with a vector (drawn as an arrow), the length of the arrow represents the speed of the body, and the arrow points in the direction the body is moving at that instant.