6.6.3.2 Perfect Black Bodies and Radiation

Question 1

What happens to the intensity and wavelength distribution of any emission when the body is hotter?

Answer 1

• greater amount of radiation released per second (more powerful)
• greater amount of shorter-wavelength radiation released

Question 2

What happens when a body is at constant temperature?

Answer 2

• absorbs radiation at same rate as it is emitting it

Question 3

When does the temperature of the body increase?

Answer 3

• when body absorbs radiation faster than it emits radiation

Question 4

What does the temperature of the Earth depend on?

Answer 4

• rates of absorption
• emission of radiation
• reflection of radiation into space

Question 5

How is the temperature of a body related to the balance between incoming radiation absorbed and radiation emitted?

Answer 5

• sun’s energy mostly absorbed by earth’s atmosphere and some is reflected
• amount of energy re-radiated and absorbed leads to earth’s temperature