Understanding Mass, Volume, and Density

Study Notes

Mass is the amount of matter in an object. Measured in grams (g) or kilograms (kg). It represents the amount of "stuff" in an object.
Volume is the amount of space an object occupies. Measured in cubic centimeters (cm³) or liters (L). It indicates the space filled by an object.
Density is a measure of how much mass is packed into a volume. Calculated by dividing mass by volume. A higher density indicates more mass concentrated in a smaller volume. Density = Mass / Volume

Regular Shaped Objects: Calculate volume using formulas (cubes, rectangular prisms, cylinders). For example, volume of a rectangular prism = length × width × height.
Irregular Shaped Objects: Use water displacement. Submerge the object in a known volume of water and measure the change in volume. The difference equals the object's volume.

Different substances have different densities due to varying atomic/molecular packing.
Density helps identify unknown materials if its mass and volume are known.
Materials float if their density is less than water's (approximately 1 g/cm³). Denser materials sink.

Temperature: Density changes with temperature. Warming usually decreases density, and cooling usually increases it.
Material: Different materials have different densities (e.g., lead is denser than wood).
State of Matter: Solids generally have higher densities than liquids, and liquids have higher densities than gases.

Gold is denser than water.
Wood is less dense than water.
Archimedes used buoyancy and density principles in his inventions.
Knowing material density helps engineers determine if a bridge can be built in certain environments.
Density explains why some objects float and others sink.