Work, Energy and Conservation
Track energy stores and transfers and calculate work, gravitational potential energy and kinetic energy.
How to study National 5 Physics
Move from a physical situation to a model, relationship, calculation and evidence-based conclusion, while using current official documents for exact assessment conditions.
Core concepts
Concept 1
Work done transfers energy when a force acts through a distance or displacement.
Exam cue: Draw an initial-to-final energy account.
Concept 2
Gravitational potential energy depends on mass, gravitational field strength and height.
Exam cue: Use the vertical height change for gravitational potential energy.
Concept 3
Kinetic energy depends on mass and the square of speed; total energy is conserved while useful forms can decrease.
Exam cue: Keep the square on speed and account for dissipated energy.
Risk pitfalls and guardrails
Saying energy is lost when it is transferred to thermal or other stores.
Guardrail: Check the model, assumptions, prefixes, units, significant figures and whether every conclusion is supported by evidence.
Using slope length instead of vertical height.
Guardrail: Check the model, assumptions, prefixes, units, significant figures and whether every conclusion is supported by evidence.
Forgetting that doubling speed quadruples kinetic energy.
Guardrail: Check the model, assumptions, prefixes, units, significant figures and whether every conclusion is supported by evidence.
Memory anchors
Work done
Force times distance in the force direction.
GPE
Mass × gravitational field strength × height.
Kinetic energy
One half × mass × speed squared.
Conservation
Total energy before equals total energy after.
Dissipation
Energy spreads into less useful stores; it is not destroyed.
Height
Use vertical change, not path length.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
What is work done?
A 25 N force moves a box 4.0 m in its direction. Work done?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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