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P2 - Energy transfer by heating - Coggle Diagram
P2 - Energy transfer by heating
2.2 - Specific heat capacity
^E=mc^0
c - specific heat capacity of the substance - joules per kilogram degrees Celsius - J/kg°C
^0 - temperature change -°C
m - mass of sample - kg
^E - energy needed - J
The greater the mass of an object, the more slowly it's temperature increases when heated.
Specific heat capacity of substance is amount of energy needed to change temperature of 1kg of substance by 1°C
2.1 - Energy transfer by conduction
The higher the thermal conductivity of a material, the higher the rate of energy transfer through the material.
A thick layer of insulating material will have a low rate of energy transfer through it.
Non-metal materials, wood & fiberglass, are the best insulators of thermal energy.
Rate of thermal energy transfer through a material depends on; temperature difference across material, thickness of material, thermal conductivity of material.
Metals are the best conductors of thermal energy.
To reduce rate of thermal energy transfer; have low thermal conductivity, thick as possible.
2.3 - Heating and insulating buildings
Cavity wall insulation is insulation used to fill the cavity between the two brick layers of an external house wall.
The rate of energy transfer from houses can be reduced by using loft insulation, cavity wall insulation, double-glazed windows, aluminum foil behind radiators, and having external walls built with thicker bricks that have lower thermal conductivity.
Houses are heated by electric or gas heaters, oil or gas central heating systems or by solid fuel in stoves or fireplaces.