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Cee, , Basic Sclence : Physica ‘. 1.4 Unita and Measurements, , Following are sore derived quantities with their units and symbol of unit, Table 1.2, , , , , , , , Derived physical, eee, , Derived unit ($.1) Symbol of unit |, , , , , , square ny metre, , , , Volume cuble metre, , , , , , ‘Velocity :, Acceleration, , , , , metre/sec, , metre/sec?, , , , , , , , , Force newton, , , , Pressure newton/metre?, , , , , , Density kilogram/metre’, , metre/sec, , , , aan of unit (Definition) : A end of unit, f a class of units consisting components from a hincemardah, (base) set of units., , Units are broadly categorized into two groups i.e, fundamental units and derived units., , In the year 1832, the German mathematician Carl Friedrich Gauss advised to select three fundamental, quantities. Considering length, mass and time as base units, available systems of units are C.GS., M.KS., F.P.S, and SI. systems., , Many systems of base units are available in engineering. They are divided into different groups. The system of, units which are in use are (i) C.G.S., (ii) M.K-S., (iii) F.P.S. and (iv) S.1., , Here length, mass and time are taken as basic physical quantities. Using this basic quantities, many physical, quantities can be derived., , (i) | C.G.S. system : In this system, the units of length, mass and time are Centimetre, Gram and Second, respectively., , (ii) MKS. system : In this system, the units of length, mass and time are Metre, Kilogram and Second, respectively., , (iii) F.P.S. system : In this system, the units of length, mass and ‘time are Foot, Pound and Second, respectively., , (iv) SL system: S.L is the abbreviation of the French name System Internationale (International system of, units)., , Different systems of units are very confusing for sharing scientific information between different regions of, world, Hence common system of units called System International (SI system) or International system of units was, accepted in International General Conference of weights and measures in Paris. There are seven base units in the, system, from which other units are derived. This system was formerly called the MKS system., , Table 1.3, System) | Length Mass Time, a ~ CGS system a centimetre gram second, a MKS system metre kilogram second, , 3, FPS system foot pound, , 4, SI system means System International (International system of units)