A physical quantity is a property of an object that can be measured with a measuring instrument.
A physical quantity is usually expressed as “a magnitude (numerical value) and a physical unit or more”
Normal body temperature of a healthy human being is 37 0C
37 is the number (value) +
0C is the unit
Systems of units
We had several systems for units which might still be used in some countries.
SI units “International system of units”
Basic SI units (we will start only with three of them
|Quantity||Name of SI Unit||Symbol||Device used to measure|
the first three is enough for starting our course, the rest will be studied later