Section 5 Density and pressure


Notes
Step 2 Calculate the answer by putting the numbers into the equation.
ρ=  20.0 

 20 
= 1.0g/cm3

ALWAYS REMEMBER TO STATE THE UNIT FOR CALCULATED QUANTITIES.

  • Determining the density of an irregularly shaped object

    In the procedure below we use the displacement of water to determine the volume of an irregular object.

Method

  1. Measure the mass m of the irregularly shaped object, in this case a stone, using an electronic balance.
  2. Partially fill a measuring cylinder with a known volume X of water.
  3. Lower the stone gently into the water until it is completely immersed, taking care not to lose water due to splashing.
  4. Measure the new volume Y.
  5. The volume of the stone is V = YX.
  6. Use the following equation to calculate the density.

Remember: Always measure to the bottom of the meniscus when using a measuring cylinder.

 
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