P 1.3 Energy transfer by heating Flashcards
(12 cards)
What is meant by energy transfer by heating?
It is the movement of energy from a hotter object to a cooler one due to a temperature difference.
What is specific heat capacity (SHC)?
The amount of energy needed to raise the temperature of 1 kg of a substance by 1°C.
What is the formula for specific heat capacity?
Q = mcΔT
Where:
Q = energy transferred (J)
m = mass (kg)
c = specific heat capacity (J/kg°C)
ΔT = temperature change (°C)
What is thermal conductivity?
A measure of how well a material conducts heat.
What kind of materials have high thermal conductivity?
Metals — they transfer heat quickly.
How do insulating materials reduce energy transfer?
By having low thermal conductivity and trapping air, reducing conduction and convection.
Name three ways to reduce heat loss in buildings.
Loft insulation, cavity wall insulation, double glazing.
What is the role of air in insulation?
Air is a poor conductor; it reduces heat transfer by conduction and limits convection.
How does loft insulation reduce energy loss?
It traps air in fibres, reducing conduction and convection through the roof.
How does cavity wall insulation work?
It fills the wall cavity with foam that reduces heat loss by conduction and prevents convection currents.
What is the effect of thicker walls or better insulating materials on heat transfer?
They reduce the rate of energy transfer by conduction, keeping buildings warmer.
Why is it important to reduce energy loss in homes?
To improve energy efficiency, save money, and reduce environmental impact.
