Continue from chp 8

Radiation
What is radiation?

Definition:
Radiation is the continual emission of infrared waves from the surface of all bodies, transmitted without the aid of a medium.

Absorption of infrared radiation:

Infrared radiation is absorbed by all objects and surfaces, especially things with dull, black surfaces, and causing a rise in temperature.

Emission of infrared radiation:

It is emitted by all objects and surfaces, causing temperature to fall.

Factors affecting rate of infrared radiation:

1) Colour and texture of the surface
2) Surface temperature
3) Surface area

Common applications of radiation

1) Teapot
2) Greenhouse
3) Vacuum flasks (Use conduction, convection, radiation and evaporation)