Sunday, June 14, 2009

Radiation

Radiation
Definition: Continual emission of infrared waves from the surface of all bodies, transmitted without the aid of a medium.
In other words, heat energy is transmitted from a hot object to another in the form of infra-red.

As this process of thermal energy transfer do not require medium, thus it can also take place in vacum. That is the reason why Earth is able to receive the thermal energy from the sun.
The electromagnetic waves emitted by the Sun makes us feel warm. Thermal energy from infrared waves is called radiant heat.
Radiation can be transmitted through solids, liquids and gases.

The higher the temperature of the heat source, the higher the frequency of the infra-red radiation it will transmit. High frequency radiation is more penetrating than the low frequency infra-red radiation.
Frequency=the number of times a wave repeats itself in a given time.

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