Distance, Displacement and Speed
Learning to distinguish distance from displacement and calculate speed.
Core concept
Speed is calculated as distance travelled divided by time taken (Speed = Distance/Time) and is a scalar quantity, while velocity is calculated as displacement divided by time (Velocity = Displacement/Time) and is a vector quantity, including direction. A car driving around a circular track back to its starting point has covered a large distance but has zero displacement, meaning its average velocity for the trip would be zero, even though its average speed is not.
Exam highlight
Key diagram

Keywords worth remembering
Trending
Most searched
Study resources
Notes & downloads
Quick notes
• Distance: total path length covered (scalar). Displacement: shortest straight-line distance with direction (vector).
• Speed = Distance/Time (scalar). Velocity = Displacement/Time (vector).
• Displacement can be zero even if distance travelled is large (e.g., a round trip).
• A car completing a circular loop has zero displacement but non-zero distance travelled.