What is Density in Physics?

Understanding Density

• Density is a measure of how compact matter is, or how much "stuff" is squeezed into a space.
• The more matter is squeezed into a space, the denser it will be.

Density in Science and Math

• Density is a comparison of the mass of an object to its volume.
• The formula for density is: ρ = m / V, where ρ is density, m is mass, and V is volume.
• In physics, density applies to the laws of nature, focusing on objects and matter.
• In mathematics, density is a formula that can be calculated and manipulated.

Calculating Density

• Density and mass are related but not the same; a denser matter will typically weigh more.
• The formula for density can be used to calculate density in different units, such as kilograms per cubic meter or grams per cubic centimeter.

Examples of Density

• Solids are generally denser than liquids, and liquids are denser than gases.
• Density examples of common elements and substances include:
  • Air - 1.23 kg/m3
  • Carbon dioxide - 2 kg/m3
  • Water - 997 kg/m3
  • Wax - 960 kg/m3
  • Diamond - 3,500 kg/m3
  • Glass - 2,500 kg/m3
  • Brass - 8,530 kg/m3
  • Stainless steel - 7,800 kg/m3
  • Lead - 11,340 kg/m3

Density in Everyday Life

• Density affects how clouds form and why they float at different altitudes in the sky.
• Water vapor is less dense than air, so it rises and cools, forming clouds as it condenses into tiny water droplets.
• The density of a cloud depends on the amount of water vapor in it, making heavy, dark rain clouds lower in the sky and wispy, high clouds float higher.
• Density affects how objects behave in water, with items that are less dense than water (997 kg/m3) floating, and those that are denser sinking.

Learn about density and its importance in various areas of life, including its impact on cloud movements and objects in water.