4.1.2 Conservation and dissipation of energy

State that energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed and so the total energy in a system does not change

Explain that only some of the energy in a system is usefully transferred, with the rest ‘wasted’, giving examples of how this wasted energy can be reduced

Explain ways of reducing unwanted energy transfers and the relationship between thermal conductivity and energy transferred

Describe how the rate of cooling of a building is affected by the thickness and thermal conductivity of its walls

Required practical 2: investigate the effectiveness of different materials as thermal insulators and the factors that may affect the thermal insulation properties of a material.

Calculate efficiency by recalling and applying the equation: [ efficiency = useful power output / total power input ]

Suggest and explain ways to increase the efficiency of an intended energy transfer