Scalar and vector quantities - EdexcelVector quantities
Scientists often make measurements. The physical quantities they measure fall into two categories: scalars and vectors. Scalar and vector quantities are treated differently in calculations.
Vector quantities have both magnitudeThe size of a physical quantity. and an associated direction. This makes them different from scalar quantities, which just have magnitude.
Examples of vector quantities
Some examples of vector quantities include:
force 鈥 eg 20 newtons (N) to the left
weight 鈥 eg 600 newtons (N) downwards
displacement 鈥 eg 50 kilometres (km) east
velocity 鈥 eg 11 metres per second (m/s) upwards
acceleration 鈥 eg 9.8 metres per second squared (m/s2) downwards
momentum 鈥 eg 250 kilogram metres per second (kg m/s) south west
The direction of a vector can be given in a written description, or drawn as an arrow. The length of an arrow represents the magnitude of the quantity. If one arrow is twice as long as another, it represents a force which has twice the magnitude.
The diagrams show three examples of vectors, drawn to different scales.