infrared radiation and temperature

• What is infrared radiation felt as?

  Heat
• What is a common misconception about infrared radiation?

  Only hot objects emit infrared radiation
• What do all objects do with infrared radiation?

  Emit and absorb infrared radiation
• How is infrared radiation emitted from an object?

  From the surface of the object
• What happens to infrared radiation emission as an object's temperature increases?

  It radiates more infrared radiation
• What occurs when an object is hotter than its surroundings?

  It emits more radiation than it absorbs
• What happens to a cooler object in warmer surroundings?

  It absorbs more infrared radiation than it emits
• What is true about objects at a constant temperature?

  They emit and absorb infrared radiation at the same rate
• Which color surface is better at absorbing and emitting radiation?

  Black surface
• How does surface area affect absorption and emission of radiation?

  Smaller surfaces absorb and emit better
• What experiment can demonstrate absorption of infrared radiation?

  • Use a Bunsen burner and candles
  • Set up two metal plates: one matt black, one silver
  • Attach ball bearings with wax to each plate
  • Observe which ball bearing falls first
• What will happen to the ball bearing on the black plate?

  It will fall first due to better absorption
• Why does the wax on the black plate melt before the silver plate?

  Black absorbs more infrared radiation
• What is the purpose of the experiment with the ball bearings?

  To show absorption of infrared radiation
• What are the key points about infrared radiation and temperature?

  • Infrared radiation is felt as heat
  • All objects emit and absorb infrared radiation
  • Hotter objects emit more radiation
  • Cooler objects absorb more radiation
  • Constant temperature means equal emission and absorption
  • Surface color and area affect absorption and emission