Subsection 2.4.2 Properties of Mass
Here are the key properties and characteristics of mass:
Intrinsic Property.
Mass is an invariant, intrinsic property of an object, meaning it does not change regardless of the object’s location or the external forces acting on it. This is in contrast to weight, which varies from place to place depending on the gravitational field strength.
Conservation of Mass.
The principle of the conservation of mass states that in a closed system, the total mass remains constant over time, regardless of the processes occurring within the system.
Inertia.
Mass is a measure of an object’s resistance to changes in its motion. The greater the mass, the more force is required to change its state of motion (i.e., to accelerate it). This relation is expressed by Newton’s Second law of motion:
\begin{equation*}
F = ma\text{.}
\end{equation*}
Gravitational Attraction.
Mass is the source of gravitational attraction. According to Newton’s law of universal gravitation, the force of attraction between two masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
\begin{equation*}
F=G\frac {m_1m_2}{r^2}
\end{equation*}
where \(F\) is the gravitational force acting between two objects, \(m_1\) and \(m_2\) are the masses of the objects, \(r\) is the distance between the object, and \(G\) is the universal gravitational constant.
Equivalence of Mass and Energy.
According to Einstein’s theory of relativity, mass and energy are equivalent and can be converted into each other. This is expressed in Einestein’s famous equation
\begin{equation*}
E=mc^2\text{.}
\end{equation*}
