Mass

Mass, abbreviated as m, is the amount of matter an object has.  It is the property of a body that causes it to have weight in a gravitational field.  It is sometimes used interchangeably in place of weight.  Mass is a scalar quantity having magnitude and is independent of any specific direction.

Weight is a vector quantity that depends on the gravity at a specific location.  The mass of an object is different from its weight, which is the force exerted on the object by gravity.  Mass is a fundamental property of matter, whereas weight is dependent on the object's mass and the acceleration due to gravity.

 

Mass formula
\( m \;=\; \rho \; V  \)     (Mass) \( \rho \;=\;   m \;/\; V   \)  \( V \;=\; m \;/\; \rho   \)
Symbol	English	Metric
\( m \) = Mass	\(lbm\)	\(kg\)
\( \rho \)   (Greek symbol rho) = Density	\(lbm \;/\; ft^3\)	\(kg \;/\; m^3\)
\( V \) = Volume	\(ft^3\)	\(m^3\)

 

Mass Types

Gravitational Mass  -  The mass of an object as measured by its interaction with gravity, it is equal to its inertial mass.
Internal Mass  -  The mass of an object measured by its resistance to acceleration when a force is applied.
Invariant Mass  -  The inferred value of the mass is independent of the reference frame in which the energies and momentum are measured so that the mass is invariant.
Mass Diffusivity  -  A proportionality constant between the molar flux due to molecular diffusion and the gradient in the concentration of the species.
Molar Mass  -  The mass of a given compound equal to its molecular mass in gram.
Relativity Mass  -  The mass of a body in motion relative to the observer.
Rest Mass  -  Rest mass of a body is measured when the body is at rest and motionless and is also relative to an observer moving or not moving.