Measuring Density

Equipment List

Resolution of measuring equipment:

• 30 cm ruler = 1 mm

• Vernier calipers = 0.01 mm

• Micrometer = 0.001 mm

• Digital balance = 0.01 g

Experiment 1: Measuring the Density of Regularly Shaped Objects

• The aim of this experiment is to determine the densities of regular objects by using measurements of their dimensions

Variables:

• Independent variable = Type of shape / volume

• Dependent variable = Mass of the object

Place the object on a digital balance and note down its mass

1. Use either the ruler, Vernier calipers or micrometer to measure the object’s dimensions (width, height, length, radius) – the apparatus will depend on the size of the object

2. Repeat these measurements and take an average of these readings before calculating the density

An example of a results table might look like this:

Analysis of Results

• Calculate the volume of the object depending on whether it is a cube, sphere, cylinder (or other regular shape)

Remember to convert from centimetres (cm) to metres (m) by dividing by 100

1 cm = 0.01 m

50 cm = 0.5 m

Using the mass and volume, the density of each can be calculated using the equation:

Where:

• ρ = density in kilogram per metres cubed (kg/m3)

• m = mass in kilograms (kg)

• V = volume in metres cubed (m3)