# Energy in the National Curriculum, 2014

### KS3 Physics

#### Energy

Calculation of fuel uses and costs in the domestic context

• comparing energy values of different foods (from labels) (kJ)
• comparing power ratings of appliances in watts (W, kW)
• comparing amounts of energy transferred (J, kJ, kW hour)
• domestic fuel bills, fuel use and costs
• fuels and energy resources.

Energy changes and transfers

• simple machines give bigger force but at the expense of smaller movement (and vice versa): product of force and displacement unchanged
• heating and thermal equilibrium: temperature difference between two objects leading to energy transfer from the hotter to the cooler one, through contact (conduction) or radiation; such transfers tending to reduce the temperature difference: use of insulators
• other processes that involve energy transfer: changing motion, dropping an object, completing an electrical circuit, stretching a spring, metabolism of food, burning fuels.

Changes in systems

• energy as a quantity that can be quantified and calculated; the total energy has the same value before and after a change
• comparing the starting with the final conditions of a system and describing increases and decreases in the amounts of energy associated with movements, temperatures, changes in positions in a field, in elastic distortions and in chemical compositions
• using physical processes and mechanisms, rather than energy, to explain the intermediate steps that bring about such changes.

#### Matter

Energy in matter

• changes with temperature in motion and spacing of particles
• internal energy stored in materials.

### KS4 Physics

#### Energy

• energy changes in a system involving heating, doing work using forces, or doing work using an electric current: calculating the stored energies and energy changes involved
• power as the rate of transfer of energy
• conservation of energy in a closed system, dissipation
• calculating energy efficiency for any energy transfers
• renewable and non-renewable energy sources used on Earth, changes in how these are used.

#### The structure of matter

• calculating energy changes involved on heating, using specific heat capacity; and those involved in changes of state, using specific latent heat