Page 150 - York Global Science 6 - Physical Science
P. 150
Cooler particles take the place of the warmer particles. These cooler particles
then gain heat energy when they are close to the heat source. As the warmer
particles cool again, they move back down and the whole process happens
again until all the particles are the same temperature.
Think!
How can we speed up the process of convection?
Give an example of when convection is useful.
Radiation
Radiation is the transfer of heat energy through waves. Two objects do not
need to be in contact with each other for radiation to happen. Heat energy
travels from objects such as the Sun or a fire. When it meets an object, it
spreads through that object by conduction or convection.
Think!
How can you reduce the amount of heat energy transferred to an object from
radiation?
The movement of heat energy happens until an object reaches thermal
equilibrium. This means that the temperature is the same everywhere. There
is no temperature difference between two objects or in a substance.
If there is no temperature difference between objects, there will be no heat
transfer.
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