Speed vs Velocity: what's the difference?

GCSE Physics

Both measure how fast something moves, but velocity also includes direction.

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Speed vs Velocity — side by side

SpeedVelocity
Type of quantityScalar (size only)Vector (size + direction)
Includes direction?NoYes
Unitm/sm/s
Can it be negative?NoYes (opposite direction)

Exam tip — how to tell them apart: Velocity = speed + direction. If a question mentions direction (or a change of direction at constant speed), it wants velocity.

Common trap: An object going round a circle at constant speed has a changing velocity, because its direction changes.

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