Defining Mass vs. Volume
Mass is the measure of the amount of matter, or 'stuff,' an object contains. It is typically measured in kilograms (kg) or grams (g). Volume is the measure of the amount of three-dimensional space an object occupies, measured in units like cubic meters (m³) or liters (L). While related, they are distinct physical properties.
Section 2: Core Principles
A key principle is that an object's mass is constant regardless of its location. For instance, your mass is the same on Earth as it is on the Moon. Volume, however, can change. For example, the volume of a gas can increase or decrease with changes in temperature and pressure, even though its mass remains the same.
Section 3: A Practical Example
Consider a classic riddle: what weighs more, a pound of feathers or a pound of lead? They have the same weight, and therefore the same mass. However, their volumes are drastically different. The pound of feathers takes up a much larger amount of space (high volume) than the small, dense pound of lead (low volume).
Section 4: Importance in Science
Understanding the difference between mass and volume is fundamental for calculating an object's density. Density, which is mass divided by volume, is a crucial intensive property used to identify substances and explain why some objects, like a ship, float while others, like a rock, sink in water.