Speed = distancetime (scalar). Velocity = displacementtime (vector).
Acceleration = change in velocitytime: a = (v − u)/t.
Distance-time graphs: gradient = speed. Flat = stationary. Curved = accelerating.
Velocity-time graphs: gradient = acceleration. Area under = distance. Flat = constant velocity.
Stopping distance = thinking distance + braking distance. Thinking distance affected by: speed, tiredness, alcohol. Braking distance affected by: speed, road conditions, brake quality, mass of the vehicle, and tyre condition. Braking distance increases with the square of the speed.