Thermal Capacity & Insulation
Science Practicals: GCSE, topic 3.1.2
Uses of Energy Transfer
Conduction, convection, and radiation are used a lot in everyday life.
Solar panels
- The solar panels that generate electricity are dark so that they can absorb the maximum amount of the sunlight hitting them.
Radiators
- Radiators are used for heating.
- A radiator’s primary way of heating a room is actually convection.
- If the primary way was radiation, then they should be painted black, as this is the colour that best emits radiation.
Vacuum flasks
- A vacuum flask keeps drinks hot or cold.
- Outside of the container, there is a vacuum layer (with no air in) surrounded by walls lined with silver.
- There aren’t any particles in the vacuum layer, so heat cannot be lost to the environment via conduction or convection.
- The silvered walls are good reflectors and poor emitters of heat. This also reduces the heat transferred by radiation.
Test yourself on Thermal Capacity & Insulation
What are the units of thermal capacity?
If the thermal capacity is 100 J/°C, which combinations of mass and specific heat capacity (SHC) could be true?
A glass jar has a metal lid that’s difficult to unscrew. Why does holding the jar under a hot tap help to open the lid?
Why are solar panels black?