Conservation and dissipation of energy

The principle of conservation of energy states that energy cannot be created or destroyed, only transferred.
Energy can be transferred from one form to multiple others in a system. Dissipated or wasted energy is the energy that has transferred into a form that isn’t useful.
Heat losses can often be reduced using thermal insulation.
- Thermal conductivity is the rate at which heat is transferred through a material.
- Insulators have very low thermal conductivities.
Ways of reducing energy losses are present in many parts of everyday life.
- Buildings use thick, insulating walls and double glazed windows to keep heat inside.
- Cars are streamlined to reduce heat lost to air resistance.

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