Energy Transfers & Systems (Edexcel GCSE Physics Combined Science): Revision Notes

Energy Transfers & Systems

When a system changes, energy is transferred

System- single object or group of objects that you are interested in.

Closed system- the net change in energy is zero. When a system changes, some energy is dissipated and stored in less useful ways. (__Dissipated: spreads out) Efficiency of transfer- proportional to the total energy supplied and ends up in useful energy stores.

Sankey diagrams - Use diagrams to show how efficient a transfer is

How energy is transferred:

• Heating When heating a pan, energy is transferred into the system by heating thermal energy stores so it increases in temperature. When heating a camping stove, energy is transfers from chemical energy store of it which increases temp

• Forces doing work When an object (system) is lifted work is being done against gravity So causes energy transferred to its kinetic & GPS

• Electrical equipment Electrical devices work by transferring energy between different energy stores