Colour and Heat: The Science of Absorption
Activity 3.10: Effect of Color on Heat Absorption is designed to demonstrate how different colours, specifically black and white, absorb heat differently. This is a concept that’s not only interesting in physics but also very relevant to everyday life, like choosing clothing based on the season.
Objective
To understand how dark and light colours absorb heat differently and why this matters in practical scenarios like clothing choices.
Materials Needed
- Two identical tin cans
- Black and white paint
- Water
- Thermometer (optional)
Steps to Follow
- Paint the Cans: Paint the outer surface of one can black and the other white.
- Fill with Water: Pour equal amounts of water into each can.
- Sun Exposure: Place the cans in the midday sun for about an hour.
- Measure Temperature: After an hour, measure the temperature of the water in both cans. If you don’t have a thermometer, you can gently touch the water to feel which one is warmer.
Expected Observations
- The water in the black can will likely be warmer than in the white can.
- This difference in temperature can be felt even by touching the water.
Understanding the Concepts
- Heat Absorption by Colors: Dark colours, like black, absorb more heat from the sun compared to light colours, like white. This is why the water in the black can gets warmer.
- Heat Reflection by Colors: Light colours reflect most of the heat that falls on them, which is why the water in the white can stays cooler.
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Conclusion
This activity shows that the colour of an object affects how much heat it absorbs from the sun. Dark colours absorb more heat, making them suitable for winter clothing, as they help keep us warm. Light colours, reflecting most of the heat, are more comfortable to wear in summer. This principle is not only useful for understanding seasonal clothing choices but also has applications in building design and other areas where temperature regulation is important.
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