P6: INFRARED RADIATION

Question 1

The hotter an object is compared to its _____, the _____ IR it emits. This causes it to eventually ______.

Answer 1

the hotter an object is compared to its surroundings, the more IR it emits. This causes it to eventually cool down

Question 2

If an object is _____ than it’s surroundings, it _______ more IR from the surroundings than it emits. Eventually the object _______.

Answer 2

If an object is cooler than it’s surroundings, it takes in more IR from the surroundings than it emits. Eventually the object warms up.

Question 3

RP - Investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface: method

Answer 3

-place a Leslie cube on a heat-resistant mat
-fill it (almost to the top) with boiling water and replace the lid
-leave for one minute to enable the surfaces to heat up to the temperature of the water
-use the infrared detector to measure the intensity of infrared radiation emitted from each surface/temp of the surface (make sure that the detector is the same distance from each surface for each reading)

Question 4

RP - Investigate how the amount of infrared radiation absorbed or radiated by a surface depends on the nature of that surface: conclusions

Answer 4

-more infrared radiation detected from the black surface than the white one
-more infrared radiation detected from matt surfaces than the shiny ones

Question 5

What colour is the worst absorber?

Answer 5

silver

Question 6

What colour is the best absorber?

Answer 6

black

Question 7

What colour is the best emitter?

Answer 7

black

Question 8

What colour is the worst emitter?

Answer 8

silver

Question 9

What colour is the worst reflector?

Answer 9

black

Question 10

What colour is the best reflector?

Answer 10

silver