Units and Measurements — Chapter Summary

A unit is a standard measure

A unit is a standard measure of any physical quantity. The SI (System International) uses seven fundamental units: metre (m) for length, kilogram (kg)

Fundamental quantities are independent physical quantities

Fundamental quantities are independent physical quantities that cannot be expressed in terms of other quantities. Derived quantities depend on fundame

Length measurement ranges from atomic scales

Length measurement ranges from atomic scales (10⁻¹⁵ m) to astronomical distances (10²² m). Techniques include direct measurement for small distances,

Dimensions represent the physical nature

Dimensions represent the physical nature of quantities using symbols [L], [M], [T], [K], [I], [C], [mol]. Dimensional formula expresses derived quanti

Systematic errors are consistent deviations due

Systematic errors are consistent deviations due to faulty instruments or methods. Random errors are unpredictable variations minimized by repeated mea