Reducing Unwanted Energy Transfer
Physics: Edexcel IGCSE, topic 4.2.4
Reducing Unwanted Energy Transfer
We take steps to reduce the amount of energy wasted.
Lubrication
- Lubrication reduces frictional forces.
- A moving object normally has at least one frictional force acting against it. This causes some energy to be dissipated.
- Lubricants can reduce the friction between the surfaces of objects that are rubbing together.
- Lubricants are normally liquids.
Thermal insulation
- Heat will be lost through the roof, windows, walls and floor.
- To reduce the energy transfer, we might:
- Fit loft insulation (the roof).
- Use double glazing (windows).
- Use cavity wall insulation (walls).
- Fit carpets (floors).
Walls in homes
- We can decrease the rate a house cools down by:
- Having thicker walls
- Having walls made from a material with a lower thermal conductivity.
- The more heat that a material conducts (the higher its thermal conductivity is), the higher the rate of energy transfer by conduction across the material.
Test yourself on Reducing Unwanted Energy Transfer
Which of these reduces energy lost through walls in homes?