Set up time 
10 mins

What you need
Thermometer, aluminium cans, black paint, white paint, silver paint, clock, cardboard, measuring jug, water

Aim
To demonstrate how some colours reflect heat, while others absorb heat. As an extension, explore thermal infrared energy, which is outside the normal colour spectrum.


efs outcomes orange illustration

Learning outcomes

1

Your students will make predictions before conducting the experiment, based on their knowledge of thermal conduction.

2

Your students will observe the effect that the three colours have on the temperature of the water.

3

Your students will use a thermometer to measure temperature, and create graphs to record results.

efs instructions orange illustration

Instructions

efs ws black white silver 1

Take three aluminium cans. Paint one black, one white and one silver. Pour identical amounts of cold water in each.

efs ws black white silver 2

Measure the starting temperature in each can. Ask students to predict which can will heat the water the most, and the least.

efs ws black white silver 3

Place the three cans in the full sun, and then measure the temperature in each can every 20 minutes.

efs ws discuss

At 60 minutes, measure the final water temperature in each can. Discuss the results and record in a graph.


In this experiment, what variables other than the can’s colour can affect the temperature?
What are some areas of your house in which the conduction of heat is good, or bad?

Time required
70 mins


efs extension orange illustration

Extension: Thermal infrared energy

Everything on earth gives off thermal energy. Scientists are using this phenomenon – and the tools to measure the thermal energy in infrared radiation – to track and monitor everything from heat waves to hurricanes.

A Simple & Cheap Solar Shower

1

All forms of matter give off thermal energy. This heat is the primary source of infrared radiation.

2

Infrared radiation (or light) is a form of light we cannot see. But we can feel it as heat.

3

Scientists use tools to measure thermal infrared radiation to study things beyond what we can see.

4

Using various instruments, scientists can predict and track major weather events around the globe.