kilogram (kg)

metre (m)

second (s)

metres per second (m/s)

metres per second squared (m/s²)

newton (N)

newtons per kilogram (N/kg)

Speed

The object is stationary.

sloping line on a distance-time graph show?,The object is moving at a constant speed.

average speed = distance moved / time taken

Use a ticker-timer or light gates to measure time over a set distance, then calculate speed.

acceleration = change in velocity / time taken (a = (v-u)/t)

Acceleration

The object is moving at a constant velocity (zero acceleration).

sloping line on a velocity-time graph show?,The object is moving with constant acceleration.

Calculate the gradient of the line.

Distance travelled

initial speed, acceleration and distance,(final speed)² = (initial speed)² + (2 × acceleration × distance) or v² = u² + 2as

It can change its speed, change its direction, or change its shape.

Gravitational force (or weight).

Friction (or air resistance/drag).

Normal reaction force.

A quantity that has magnitude (size) only.

A quantity that has both magnitude (size) and direction.

Mass is the amount of matter in an object (in kg), while weight is the force of gravity on that mass (in N). Mass is constant, weight depends on gravity.

weight = mass × gravitational field strength (W = m × g)

Thinking distance + Braking distance

The distance the vehicle travels during the driver's reaction time.

The distance the vehicle travels once the brakes are applied.

Speed, mass of the vehicle, road conditions (e.g. wet/icy), and driver's reaction time (e.g. tired, under influence).

The constant speed that a freely falling object eventually reaches when the force of air resistance is equal and opposite to the force of gravity (weight).

As speed increases, air resistance increases. Eventually, air resistance becomes equal to the object's weight. The resultant force is now zero, so acceleration is zero, and the object falls at a constant velocity.

Force = mass × acceleration (F = m × a)

A single force that has the same effect as all the forces acting on an object combined.

Zero. The object is either stationary or moving at a constant velocity.

When an object returns to its original shape after the deforming force is removed.

When an object is permanently deformed and does not return to its original shape after the force is removed.

Force = spring constant × extension (F = k × x)

The point beyond which the extension of an elastic object is no longer directly proportional to the force applied. On a graph, the line starts to curve.