NJC 2025 H2 Physics Quantities & Measurement (Student)

National Junior College Science Department | Physics 1 1. Quantities & Measurement Content Page 1.1 Physical Quantities and SI Units ................................ ................................ ................................ ........ 3 1.1.1 Importance of SI Base Units ................................ ................................ ............................... 3 1.1.2 Physical Quantities: Base Quantities and Derived Quantities ................................ .............4 Base Units ................................ ................................ ................................ .......................4 S.I. Derived Units ................................ ................................ ................................ ............5 1.1.3 Prefixes ................................ ................................ ................................ .............................. 7 1.1.4 Homogeneity of Physical Equations ................................ ................................ ...................8 Dimensional Consistency ................................ ................................ ................................ 8 Homogeneous equations ................................ ................................ ................................ .8 Reasonable estimations ................................ ................................ ................................ 10 1.2 Errors and Uncertainties ................................ ................................ ................................ .................. 11 1.2.1 Systematic Errors ................................ ................................ ................................ .............11 1.2.2 Random Errors ................................ ................................ ................................ .................12 1.2.3 Distinction between Systematic Errors and Random Errors................................ ..............13 1.2.4 Precision and Accuracy ................................ ................................ ................................ ....13 1.2.5 Experimental uncertainties ................................ ................................ ............................... 16 Expressing measurements with its uncertainty ................................ .............................. 16 Fractional and Percentage Uncertainties ................................ ................................ .......17 1.2.6 Consequential Uncertainty ................................ ................................ .............................20 Asymmetric Uncertainty ................................ ................................ ................................ .24 1.3 Scalars and vectors ................................ ................................ ................................ ......................... 25 1.3.1 Vector addition ................................ ................................ ........................