GCSE Physics Required Practical: Calculating Densities

Key Stage 4

Meaning

Finding the density of solid objects.

Experiment 1: Regular Cuboid

Method

A diagram of the apparatus used in an experiment to find the density of a regular cuboid.

1. Measure the mass of the cuboid using an electronic balance or measuring scale.
2. Measure the length, width and height of the cuboid using a ruler.
3. Multiply the length, width and height to calculate the volume.
4. Use the equation \(\rho = \frac{m}{V}\) to calculate the density of the cuboid.

Improving Accuracy

Place the electronic balance on a flat, level surface to get an accurate reading of the mass.

Improving Precision

Use a ruler with a higher resolution.

Use an electronic balance with a higher resolution.

Use a larger cuboid to reduce the uncertainty caused by the resolution of the measuring instruments.

Experiment 1: Irregular Solid

Method

A diagram of the apparatus used in an experiment to find the density of an irregular solid.

1. Measure the mass of the object using an electronic balance or measuring scale.
2. Fill a measuring cylinder with enough water to submerse the object.
3. Take a reading of the volume of water in the Measuring Cylinder.
4. Place the object in the Measuring Cylinder and ensure it is submersed.
5. Take a reading of the volume of water + object in the Measuring Cylinder.
6. Subtract the volume of water from the volume of water + object to find the volume of the object.
7. Use the equation \(\rho = \frac{m}{V}\) to calculate the density of the irregular object.

Improving Accuracy

Ensure the mass is measured at the start of the experiment so that the mass is measured while the object is dry.

Place the electronic balance on a flat, level surface to get an accurate reading of the mass.

Place the measuring cylinder on a flat, level surface and read it from eye level to get an accurate reading of the volume of water.

Improving Precision

Use an electronic balance with a higher resolution.