Chapter 2: Energy Transferred By Heating Flashcards
What are the best conductors of energy?
Metals.
What are the best insulators?
Non metal materials such as fibreglass are the best insulators such as wool and fibre glass.
How does thermal conductivity affect the energy transfer?
The higher the thermal conductivity of a material the higher the rate of energy transfer through it.
How does the thickness of an insulator affect the rate of energy transfer.?
The thicker a layer of insulation material the lower the rate of energy transfer through it.
What is the specific heat capacity of a substance?
Is the amount of energy needed to change the temperature of 1kg of the substance by 1 degrees Celsius.
What is the equation to calculate the energy needed to change the temp of the mass?
Energy transferred(joules)=mass(kg) x SHC (j/kgdegreeC) x temp change (degree C)
How does the mass of an object affect its temperature increase when heated?
The greater the mass of an object the slower its temperature will increase when its heated.
How do you find the SHC of an object practically?
Use a joule-meter and a thermometer to measure energy transferred and temperature change then put it into the equation.
How are houses heated?
Electric or gas heaters and gas or oil central heating or solid fuel stoves
How can energy transfer from houses be reduced?
- Loft insulation
- Cavity wall insulation
- Double glazed windows
- Aluminum foil behind radiators
- External walls with thicker bricks and lower thermal conductivity
What is cavity wall insulation?
It is insulation that is used to fill the cavity between the two brick layers of an external house wall.
