T6 black body radiation

Question 1

what do all bodies emit and absorb

Answer 1

infrared radiation

Question 2

what happens to the quantity of infrared radiation emitted by an object as temperature increases

Answer 2

the hotter the object, the more infrared radiation it will emit

Question 3

what is a perfect black body

Answer 3

an object that absorbs all of the radiation that is incident upon it

Question 4

how much radiation does a perfect black body reflect or emit

Answer 4

none

Question 5

why is a perfect black body the best possible emitter of radiaiton

Answer 5

• it’s a perfect absorber since it absorbs all radiation incident on it
• a perfect absorber is also a perfect emitter

Question 6

other than the intensity of radiation emitted, how does increasing the temperature of an object affect its emission

Answer 6

the wavelength distribution of any emission is dependent on the object’s temperature

Question 7

what can be said about the rates of emission and absorption for a body at a constant temperature

Answer 7

the body is absorbing and emitting radiation at the same rate

Question 8

what can be said about the rates of emission and absorption for a body increasing in temperature

Answer 8

the body is absorbing radiation faster than it is emitting it

Question 9

give 2 factors that affect the temperature of the Earth

Answer 9

1. the Earth’s rate of absorption and emission of radiation

2. the amount of reflection of radiation into space