Base quantity 1 A physical quantity is .. 2 Examples of scientific instruments stopwatch, metre rule, triple beam balance, thermometer, ammeter, voltmeter, spring balance, etc. 3 A base quantity is a physical quantity which cannot be defined to other physical quantities. 5 List of 5 basic physical quantities and their units. i) Light intensity unit candela ii) Amount of substance unit mol Derived quantities 1 A derived quantity is a physical quantity which combines several basic quantities through multiplication, division or both. 2 Determine the derived unit for the following derived quantities. t EMBED Equation.3 ForceFforce mass x acceleration F makg m s-2Newton (N)pressureP EMBED Equation.3 , P F/AN m-2Pascal (Pa)weightWweight mass x gravitational acceleration W mgkg m s-2Newton (N)workWwork force x displacement W FsN mJoule (J)powerP EMBED Equation.3 , P W/t , P E/tJ s-1Watt (W)kinetic energyEk EMBED Equation.3 Ek mv2kg m2 s-2Joule (J)potential energyEpP.E mass x gravitational acceleration x height 2. It will be written before the unit as a multiplying factor. 3. The list of prefixes 4. Some physical quantities have extremely large magnitudes. These extremely large and small values can be written in standard form or using standard prefixes. Write the quantities in standard prefixes a. Frequency of radio wave 91 000 000 Hz 9.1 x 10 1MHz b. Diameter of the earth 12 800 000 m 12.8 Mm 1.28 x 10 1 Mm c. Distance between the moon and the earth 383 000 000 m 383 Mm 3.83 x 10 2 Mm d. Mass of the earth 6 000 000 000 000 000 000 000 000 kg 6.0 x 10 12 Tm Standard Form 1 Standard form A x 10n, 1 A 10 and n integer 2 Standard form is used to simplify the expression of very large or small numbers 3 Some physical quantities have extremely small magnitudes. Write them in standard form Radius of the earth 6 370 000 m 6.37 x 106 m Mass of an electron 0.000 000 000 000 000 000 000 000 016 73 kg 1.673 x
