Displacement and velocity

Science

Definition

Displacement is the straight-line distance and direction from an object's starting position to its final position, making it a vector quantity. Velocity is the rate of change of displacement with respect to time, also a vector, unlike speed which is scalar.

Examples

  • Walking 3 blocks north then 4 blocks east gives a displacement of 5 blocks northeast, even though you walked 7 blocks total
  • A car driving around a circular track returns to its start with zero displacement despite covering the full track distance
  • An object thrown straight up and caught at the same height has zero net displacement
Key Fact

Average velocity = displacement / time (v = Δx/Δt); speed = distance / time.

Related Terms

Acceleration Speed and velocity Kinematic equations Motion graphs

Study This Concept

Practice displacement and velocity with free review games in these units:

AP Physics 1 Unit 1: Kinematics