Question

station 4: radiation
using knowledge of radiation and terms from the word bank, explain what is happening in each picture.
word bank
thermal radiation absorb emit reflect dark light
a.
b.
c.
solar panels painted black are more efficient at producing electricity.
airplanes that fly at high altitudes are typically painted white or other light colors.
heat exhaust coils on the back of refrigerators are usually painted flat black.

Explanation:

• A: Dark colors (like black) absorb more thermal radiation. Solar panels need to absorb as much energy (in the form of thermal radiation from the sun) as possible to convert it into electricity. So, painting them black (a dark color) helps in better absorption of thermal radiation, making them more efficient at producing electricity.
• B: Light colors (like white) reflect more thermal radiation. Airplanes flying at high altitudes can be exposed to a lot of solar radiation. By being painted white or other light colors, they reflect more of this thermal radiation, preventing excessive heating of the airplane's body.
• C: Dark colors (like flat - black) emit thermal radiation well. Refrigerator heat exhaust coils need to release (emit) the heat that is removed from the inside of the refrigerator. Painting them black (a dark color) enhances their ability to emit thermal radiation, effectively getting rid of the heat.

Answer:

• A: Dark colors (black) absorb thermal radiation well, so solar panels painted black absorb more solar thermal radiation for efficient electricity production.
• B: Light colors (white/light) reflect thermal radiation. Airplanes at high altitudes painted light reflect more solar thermal radiation, avoiding over - heating.
• C: Dark colors (flat - black) emit thermal radiation well. Refrigerator heat exhaust coils painted black emit the heat (thermal radiation) removed from the fridge effectively.