Density, Thermal Energy Equations, Latent Heat & Reducing Energy Transfer

Use the density equation

Density = mass ÷ volume. ( given in exam )

Recall the equation for change in thermal energy

Change in thermal energy = mass × specific heat capacity × change in temperature.

State the units for change in thermal energy

Joules (J)

State the units for specific heat capacity

Joules per kilogram per degree Celsius (J/kg °C).

State the units for temperature change

Degrees Celsius (°C).

Recall the equation for thermal energy during a change of state

Thermal energy = mass × specific latent heat.(given in exam)

Explain ways to reduce unwanted energy transfer

Use thermal insulation to reduce heat loss.

Explain how insulation reduces energy transfer

Insulation reduces conduction, convection and radiation.

Give examples of thermal insulation

Loft insulation, cavity wall insulation, double glazing, draught excluders.

Explain why air is a good insulator

Air has low thermal conductivity.