density physics

• Density


  A measure of the compactness of a substance, relating the mass of a substance to the amount of space it takes up
• The Particle Model can explain density
• Density


  The mass of a substance per unit volume
• The units of density are kg/m³ (the mass is in kg and the volume is in m³)
• 1 g/cm³ = 1000 kg/m³
• Calculating density


  1. Plug the mass and volume into the density equation

  2. Round the answer to the correct number of significant figures

  3. Check the units match what's given in the question
• Density


  • Depends on what the object is made of and how its particles are arranged
  • A dense material has its particles packed tightly together, while a less dense material has its particles more spread out
• Solids are generally denser than liquids, and gases are usually less dense than liquids
• Finding the density of a solid object

  1. Measure the mass using a balance

  2. If a regular solid, measure the length, width and height to calculate the volume

  3. For an irregular solid, submerge it in a eureka can filled with water and measure the displaced volume
• Finding the density of a liquid

  1. Place a measuring cylinder on a balance and zero it

  2. Pour 10ml of the liquid into the cylinder and record the mass and volume

  3. Repeat step 2 until the cylinder is full, recording each measurement

  4. Use the density equation to calculate the density for each measurement

  5. Take the average of the calculated densities
• The volume of a cube is equal to length x width x height
• You need to know the formulas for calculating the volume of different shapes