Science explained

Motion, speed and acceleration

Motion is described relative to a reference point, while speed and acceleration describe how position and velocity change over time.

PhysicsMotion

Editorial review: August 12, 2026 · Julian E. Marston

Speed

Average speed is distance travelled divided by elapsed time.

Velocity

Velocity includes direction as well as magnitude.

Acceleration

Acceleration means velocity is changing—speeding up, slowing down or changing direction.

Graphs tell the story

Position-time and velocity-time graphs can reveal motion more clearly than a list of numbers.

This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.