Physical
quantities
Physical
quantities are well defined measurable properties.
Examples
Length
Mass
Speed
Temperature
Good, bad or
happiness are things in our life , they’re not measurable, therefore not Physical
quantities
Units
Unit is a
standard amount ( part) of a given Physical quantity , which use to measure
that specific physical quantity as how
many standard such parts are included for a given quantity.
Examples
For length
– meter, feet, mile ect……….
For time –
seconds, minutes, days ect…………
Basic quantities and Derived quantities
Physical
quantities are divided in to two groups by considering their nature and
applications
1) Basic (fundamental) quantities
2) Derived (secondary) quantities
Base
quantities
|
Base quantity |
Name |
Symbols |
|
Length Mass Time Electric current The modynamic temperature Amount of substance Luminous intensity |
Metre Kilogram Seconds Ampere Kelvin Viole candela |
m kg s A K mol cd |
Ø Physical
quantities have a numerical value and a unit.
Eg :- 10kg, 10s, the
value, kg is the unit
Ø These
are physical quantities
Eg :- Mass, length, Time
Ø The
fundamental (base unit) of physical quantities.
Ø The
sI base quantities there units.
