Vehicles move on land in various ways. Speed describes how fast an object moves, but not the direction, while velocity refers to both speed and direction of motion. Acceleration measures the rate of change of velocity, whether that means speeding up, slowing down, or changing direction.

1. Chapter 5 (part 1) - Motion

4. 5.1 The motion of vehicles on land

37. 5.2 The concepts of speed, velocity& acceleration