Mass is the quantitative measure of the amount of matter in a certain object. Physics rest on the basic idea that all objects have matter and therefore, mass is a fundamental unit. It is also a scalar quantity, as it is a direct measurement. Mass is classified into three different measures: Inertial mass, potential gravitation mass, and active gravitational mass. However, no experiment has proven there to be a difference between any of the classifications of mass.
Units of Mass Edit
In SI or mass is measured in kilograms, denoted as kg. Other various units of mass are used, such as: grams(g), metric tons, pounds, slugs, and atomic mass units(amu).
Inertial Mass Edit
Inertial mass can be defined as the ratio of the net force exerted on an object to the object's acceleration. Simply put, it is the measure of an object's inertia. The more mass an object has, the less able it is to change it's motion, and therefore less force is applied to the object. The less mess an object has, it is more free to change it's motion, and therefore more mass is applied to the object. According to Newton's Second Law of Motion, the acceleration of an object is equivalent to the net force applied on the object divided by it's mass.
Assuming that the mass of a given object is constant, the force applied to the object and it's acceleration are directly proportional in a linear relationship. As applied force increases, acceleration increases and vice-versa.
Gravitational Mass Edit
In gravitational mass, Newton's Second Law of Motion is still applied. We assume that the only force acting on a certain object is a gravitational force. Acceleration of the object is denoted as g. g represents the acceleration due to gravity of an object relative to the object that is applying the gravitational force. For example, everything on this planet has a mass, and a gravitational force is applied to the masses. The acceleration due to gravity is the same for each object, in this case, 9.81m/s for the planet Earth.