1. International System of Units Measurement It is the process of assigning a number to an attribute (or phenomenon) according to a rule or set of rules. Units A unit is the chosen standard of measurement of quantity, which has the same nature as the quantity. To express any physical quantity completely, we need the numerical value and the unit ( u ). Physical quantity = nu Fundamental Units: Units for fundamental or base quantities (length, mass and time) Derived Units: Units obtained from fundamental units Example: Unit of speed ( ms −1 ) Speed ∴ Unit of speed Systems of Units CGS System: Base units for length, mass and time in this system are centimeter, gram and second respectively. FPS System: Base units for length, mass and time in this system are foot, pound and second respectively. MKS System: Base units in this system are metre, kilogram and second. International System (SI) of Units: Based on seven base units; at present the internationally accepted sy
1. Overview of Physics and Fundamental Forces in Nature: Etymological Meaning of Science Comes from the Latin verb Scientia , which means ‘to know’ Origin Science is as old as the human species. From the 16 th century onwards, great strides were made in science in Europe. Definition Science is a systematic way of acquiring knowledge about the surroundings by careful observations and experimentations over a period of time. Steps Involved in a Standard Scientific Method Systematic observation Controlled experiments Qualitative reasoning Quantitative reasoning Mathematical modelling Prediction Verification or falsification of theories Nature of Science Science is ever dynamic. There is no ‘final theory’ in science. Modifications can be made in the established scientific laws. Understanding Physics and Physical World Physics It is a branch of science. Etymological meaning: Comes from a Greek word meaning ‘nature’ Definition: Study o