Mass is a basic property of matter.
It does not depend on the temperature, pressure or location of the object in space. The SI unit of masses kilogram.
In practice following multiples and some multiples of local are used.
1 gram(g) = 10-3 kg
1 milligram (mg) = 10-6 kg
1 tonne(t) = 1000kg = 103 kg
Unified atomic mass: While dealing with atoms and molecules, the kg is inconvenient unit. In this case, there is an important standard unit of mass called the unified atomic mass unit (u) which is:
1 unified atomic mass unit =1 u = (1/12) of the mass of an atom of carbon–12 iso-top including the mass of electrons = 1.66 x 10 -27.
Range of masses
|Red blood cell||10-13|
|Milky Way galaxy||10 41|
|Observable universe||10 55|
Type of mass :There are two type of masses:
- Inertial mass and
- Gravitational mass.
The inertial mass is the characteristics of the body that determines its response to an external force in accordance with Newton’s law of motion whereas gravitational mass is the characteristics of the body that appears in the Newton’s law of gravitation.