The movement of objects can be described using motion graphs and numerical values. These are both used to help in the design of faster and more efficient vehicles.

A physical quantity is something that can be measured. Scalar quantities only have a magnitude or size.

Some examples of scalar quantities include:

- temperature, eg 10 degrees Celsius (°C)
- mass, eg 5 kilograms (kg)
- energy, eg 2,000 joules (J)
- distance, eg 19 metres (m)
- speed, eg 8 metres per second (m/s)
- density, eg 1,500 kilograms per metre cubed (kg/m³)

Vector quantities have both magnitude and an associated direction. This makes them different from scalar quantities, which just have magnitude.

Some examples of vector quantities include:

- force, eg 20 newtons (N) to the left
- displacement, eg 50 kilometres (km) east
- velocity, eg 11 metres per second (m/s) upwards
- acceleration, eg 10 metres per second squared (m/s²) downwards
- momentum, eg 250 kilogram metres per second (kg m/s) south west

The velocity of an object is its speed in a particular direction. Velocity is a vector quantity because it has both a magnitude and an associated direction. To calculate velocity, displacement is used in calculations, rather than distance.

Unlike distance, which is a scalar quantity, displacement is a vector quantity. It includes:

- the distance travelled, measured in a straight line from start to finish
- the direction of the straight line