Distance is a scalar quantity. It is simply how far an object has moved without direction involved
Displacement is a vector quantity. It measures distance and direction in a straight line from the starting point to the finishing point.
If you walk 10 metres North then 10 metres South then distance travelled is 20m.
The displacement however is 0m as you have finished at the same starting point.

Speed and Velocity both measure how fast an object is going but speed is scalar and velocity is a vector. Velocity is speed in a direction.
Speed can be constant while velocity is changing e.g. moving at the same speed in a circle (changing direction)

Equation: v = d / t and v = s / t
speed (m/s) = distance (m) / time (s) and velocity (m/s) = displacement (m in a direction) / time (s)

Typical Everyday Speeds:
Person walking - 1.5 m/s A car - 25 m/s

Person running - 3 m/s A train - 55 m/s Speed of Sound - 330 m/s
Person cycling - 6 m/s A plane - 250 m/s

	Created by Sifat Symum almost 8 years ago

GCSE Forces and Motion