Masses

Mass is a measure of the amount of matter in an object, which determines its weight and how it responds to forces like gravity. It reflects an object's inertia, meaning how much effort it takes to change its motion or position. Unlike weight, which varies with gravity, mass stays constant regardless of location. In physics, mass is fundamental because it influences how objects interact, especially through gravity and momentum. Think of mass as the "stuff" an object is made of—a numerical way to quantify its presence and resistance to changes in motion.