# GCSE Physics Required Practical: Investigating Thermal Insulators

## Key Stage 4

### Meaning

Investigate the effectiveness of different thermal insulators on reducing an energy transfer by heating.

### Experiment

#### Variables

Independent Variable: Insulating material.
Dependent Variable: The temperature decrease of water after a given time.
Control Variables: The volume of water used. The initial temperature of the water. The time taken between measurements. Thickness of the insulating material.

#### Method

 A diagram of the apparatus used in an experiment to compare the effectiveness of different thermal insulators.
1. Measure 100ml of hot water (around 50°C) using a measuring cylinder.
2. Fill a can with hot water
3. Place a thermometer in the water and wait until the temperature reaches 40°C.
4. Begin a stopwatch when the temperature is 40°C then read the temperature every 30 seconds for 5 minutes.
5. Repeat steps 1-3 with a can covered each type of insulating material.
6. Plot a graph with temperature on the y-axis and time on the x-axis plotting the results for each insulating material on the same graph.

#### Improving Accuracy

Place the cans on a heatproof mat to reduce the thermal energy lost to the table surface by conduction.
Place a lid over the cans to reduce the thermal energy lost to the air by evaporation.
Complete the experiments with different insulators simultaneously so that a change in the temperature of the laboratory does not affect the results.
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.
 A diagram including apparatus used improve the accuracy of an experiment to compare the effectiveness of different thermal insulators.

#### Improving Precision

Ensure the same amount of water (Control Variable) is used in each container to reduce the random error in repeat readings.