SEC G3 Combined Science Physics component K326/K327
CP6: Energy
Track energy stores and transfers, then calculate work, kinetic energy, gravitational potential energy, and power.
Reviewed for the 2027 cohort on 19 July 2026. The official syllabus remains authoritative for assessable wording and paper details.
Core notes
Energy accounting tracks stores before and after a process, the pathway of transfer, and the rate at which the transfer occurs.
Stores and transfer pathways
Energy may be held in kinetic, gravitational, chemical, elastic, nuclear, or internal stores. It moves between stores mechanically, electrically, by heating, or through electromagnetic and mechanical waves.
Name both the store that decreases and the store that increases. Saying that energy is simply used up hides where it went.
Kinetic, gravitational, and conserved energy
Kinetic energy depends on mass and the square of speed. Near Earth's surface, gravitational potential energy change depends on mass, field strength, and vertical height change.
Total energy remains constant in a closed system. A decrease in a useful store is matched by increases elsewhere, often including the internal energy of the surroundings.
Work and power
A force does work when it moves an object through a distance in the force's direction. Work is an energy transfer, so both are measured in joules.
Power measures how quickly energy is transferred. Two devices can transfer the same energy but have different powers if their times differ.
Formulae and relationships
| Relationship | Use |
|---|---|
| Find kinetic energy. | |
| Find gravitational potential energy change. | |
| Find work for motion in the force direction. | |
| Find power. |
Worked examples
Example 1: A load is lifted in . Take . Find the power.
- Find the energy transferred: .
- Use the full transfer time of .
- Calculate .
Answer: .
Chapter checkpoint
Use these three moves to organise the topic before attempting a mixed or practical question.
- Define the system before tracking energy stores and transfer pathways.
- Use conservation to connect kinetic and gravitational energy changes without saying energy disappears.
- Distinguish work, energy, and power through their units and time dependence.
Official outcome coverage
K326 CP6: 5 mapped outcomes, references CP6(a), CP6(b), CP6(c), CP6(d), CP6(e). Check the official K326 syllabus.
K327 CP6: 5 mapped outcomes, references CP6(a), CP6(b), CP6(c), CP6(d), CP6(e). Check the official K327 syllabus.
The outcome wording is not reproduced here. The relevant official syllabus remains authoritative for exact assessable scope.
Practical and data connection
Use measured force, distance, mass, height, speed or time data to compare work, energy change and power. Define the system, keep units consistent, identify energy transferred to the surroundings, and avoid claiming that a numerical difference proves energy was destroyed.
Exam traps and retrieval check
Avoid these traps
- Saying energy disappears.
- Forgetting that speed is squared in kinetic energy.
- Confusing energy in joules with power in watts.
Check from memory
What pathway transfers energy through a current?
Electrical transfer.
What principle closes an energy account?
Conservation of energy.
What does one watt mean?
One joule transferred per second.
Official Combined Science scope
This shared Combined Physics owner serves both K326 and K327. Energy stores and transfer pathways, kinetic and gravitational energy, conservation, work, and power.