Chapter 1.6 - 'Radiation'

Question 1

Define radiation.

Answer 1

The emission of energy as electromagnetic waves.

Question 2

Define what radiation is formally known as.

Answer 2

Electromagnetic Radiation.

Question 3

State the three effects of light hitting an object.

Answer 3

Absorption, reflection and transmission.

Question 4

Electromagnetic radiation is emitted by all objects on the basis that?

Answer 4

The object is above absolute zero.

Question 5

List the factors impacting the rate of emission and absorption.

Answer 5

1. Surface area - The larger the higher the rate of absorption and emission.
2. Temperature - The greater the difference, the greater rate of energy transfer.
3. Wavelength of the incident radiation - Matte black surfaces are almost perfect absorbers and emitters of radiant energy at all wavelengths.
4. Surface colour and texture - Roughened, dark surfaces will heat up faster than a shiny, light one.