Distance
how far an object moves along its path
Displacement
how far an object has travelled
Speed
the rate of change of distance
The equation linking average speed, distance travelled and time taken
Average speed = distance travelled ÷ time taken
The equation linking average speed, initial speed and final speed
Average speed = (initial speed + final speed) ÷ 2
The equation linking acceleration, final speed, initial speed and time taken
acceleration = (final speed – initial speed) ÷ time taken
Unit for speed and velocity
Metres per second (m/s)
Unit for distance
Metres (m)
Unit for time
Seconds (s)
Unit for acceleration/ rate of change of speed
Metres per second squared (m/s²)
Typical walking speed
Approx. 1.5 metres per second (m/s)
Typical running speed
Approx. 3 metres per second (m/s)
Typical cycling speed
Approx. 6 metres per second (m/s)
Typical speed of a car
Approx. 25 metres per second (m/s)
Typical speed of a train
Approx. 50 metres per second (m/s)
Typical speed of an aeroplane
Approx. 250 metres per second (m/s)
Speed of sound in air
Approx. 330 metres per second (m/s)