The Fundamentals of Mass
Mass is the measure of the amount of matter in a physical body. Unlike weight, which is the force of gravity on an object, mass is constant regardless of location. It is a fundamental property of matter.
Introduction
Mass is one of the fundamental properties of matter, representing the amount of substance in an object. It is intrinsic to the object and remains constant regardless of location, unlike weight which varies with gravitational field strength.
History
The concept of mass evolved from ancient balance scales to Newton's laws of motion. The kilogram was originally defined in 1795 as the mass of one liter of water. In 2019, it was redefined using Planck's constant, making it based on fundamental physical constants rather than a physical artifact.
Key Units
Kilogram (kg)
The SI base unit of mass, defined by Planck's constant since 2019.
Gram (g)
Equal to 0.001 kg, commonly used for small objects and cooking ingredients.
Pound (lb)
An imperial unit equal to approximately 0.453 kg, still widely used in the United States.
Ounce (oz)
Equal to 1/16 of a pound or approximately 28.35 grams.
Ton (metric)
Equal to 1,000 kg, used for large masses like vehicles and cargo.
Applications
- Cooking and baking recipe measurements
- Medical dosing and pharmaceutical calculations
- Shipping and logistics weight limits
- Scientific research and laboratory work
- Manufacturing quality control and specifications
- Fitness and health monitoring
Mass-Energy Equivalence
E = mc²Einstein's famous equation showing the equivalence of mass (m) and energy (E), where c is the speed of light.