Black Body Radiation (T)

• What is meant by blackbody radiation?

  Blackbody radiation refers to the radiation emitted by a perfect black body that absorbs all incident radiation.
• How does the temperature of an object relate to the balance between radiation absorbed and emitted?

  The temperature depends on the balance between radiation absorbed and emitted.
• What are the characteristics of matte black surfaces in terms of infrared radiation?

  • Best absorbers of infrared radiation
  • Best emitters of infrared radiation
• Do all objects emit and absorb infrared radiation?

  Yes, all objects emit and absorb infrared radiation regardless of their temperature.
• How does the emission of infrared radiation differ between hotter and cooler objects?

  A hotter object emits more infrared radiation than a cooler object.
• What happens to the intensity of radiation as the temperature of an object increases?

  The intensity of radiation increases with temperature.
• What is the relationship between the wavelength of radiation and the temperature of an object?

  • Hotter objects emit shorter wavelength radiation
  • Cooler objects emit longer wavelength radiation
• What defines a perfect black body in terms of radiation?

  • Absorbs all incident radiation
  • Reflects no radiation
  • Transmits no radiation
• What occurs when an object is warmer than its surroundings?

  It emits more radiation than it absorbs, causing its temperature to decrease.
• What happens when an object is cooler than its surroundings?

  It absorbs more radiation than it emits, causing its temperature to increase.
• What is the condition for an object to maintain a constant temperature?

  It absorbs radiation at the same rate as it emits radiation.
• How does the Earth gain or lose energy through radiation?

  • Absorbs radiation from the Sun
  • Emits infrared radiation back into space
• What type of radiation does the Sun emit?

  Short wavelength radiation such as visible light and ultraviolet.
• What happens to some of the Sun's radiation when it reaches the Earth?

  Some is reflected by clouds, and the rest is absorbed by the Earth's surface.
• What effect does the absorption of radiation have on the Earth's temperature?

  The absorption of radiation causes the temperature of the Earth to increase.
• What happens to the infrared radiation emitted by the Earth?

  It is partially trapped by greenhouse gases in the atmosphere.
• How does human activity affect greenhouse gas levels?

  Human activity increases the levels of greenhouse gases in the atmosphere.
• What is the consequence of increased greenhouse gases in the atmosphere?

  It traps more heat energy, reducing radiation emitted into space.
• How does cloud cover affect the Earth's energy radiation?

  • Cloudy nights tend to be warmer than clear nights
  • Clouds reflect infrared radiation back to the Earth