Heat Tips and Pieces

Question 1

Give some examples of radiation?

Answer 1

1. Greenhouse traps radiant heat energy. During the day radiant heat from the sun (infrared radiation) passes through the glass because the glass is transparent. The heat is absorbed by the plants and soil. As the plants and soil warms, they began to emit radiation, increasing the temperature.
2. Teapots and kettles are shiny and light colour to reduce heat loss.
3. Emergency blankets: Survival blanket is a thin sheet with both sides shiny, silver coloured foil. The foil reflect the person’s heat radiation back, keeping them warm.
4. Solar panels can heat water and they are dark coloured. This is because dark, matt, black surfaces are good absorbers and emitters of infrared radiation, while light, shiny surfaces are bad emitters and abosorbers of infrared radiation as they are good thermal reflectors.