OCR GCSE Combined Science A · J250
Specification P2.1c, P6.1c · Physics Paper 1, Physics Paper 2
Revise: Unit Conversion and Rate ComputationScientists use the International System of Units, usually called SI, so that measurements can be compared consistently. In motion calculations, distance is normally expressed in metres (m), time in seconds (s) and speed in metres per second (m/s). The SI unit of mass is the kilogram (kg).
- Revise: Unit Conversions and Rates
The internationally agreed system of measurement units, including the metre (m), kilogram (kg) and second (s).