KS3 Year 9 / Physics / Curriculum
Energy: structured theory, worked examples, answered practice, and a mastery checklist for KS3 Year 9.
CHAPTER PLAN
Follow the steps in order or jump directly to the part you need.
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Estimated active study time
209 minutes
Objectives, key ideas, and structured theory.
Open →Worked examples that explain every step.
Open →Graded tasks with hints and answer guidance.
Open →Assignments from core work to challenge.
Open →A timed, marked test with solution guidance.
Open →Progress is stored only in this browser and does not require AI credits.
Unit
The essential chapter ideas in a clear sequence before practice.
Define the system and identify how energy or momentum is transferred. Conservation applies to the correct system and time interval.
Write initial and final quantities before substituting numbers. This exposes losses, external work, and direction.
Energy describes an amount, while power describes its transfer rate. Do not compare systems using work alone when time matters.
For “Energy conservation”, start from an observation or model, define quantities and units where relevant, and separate the changed factor from the measured outcome. Support the conclusion with data and state the test's limitations.
For “Power”, start from an observation or model, define quantities and units where relevant, and separate the changed factor from the measured outcome. Support the conclusion with data and state the test's limitations.
For “Efficiency”, start from an observation or model, define quantities and units where relevant, and separate the changed factor from the measured outcome. Support the conclusion with data and state the test's limitations.
For “Work done”, start from an observation or model, define quantities and units where relevant, and separate the changed factor from the measured outcome. Support the conclusion with data and state the test's limitations.
For “Energy resources”, start from an observation or model, define quantities and units where relevant, and separate the changed factor from the measured outcome. Support the conclusion with data and state the test's limitations.
Physics
Follow the method step by step and check why every step is valid.
A 4 kg body moves at 6 m/s. Find its kinetic energy and momentum.
Ek = 72 J, p = 24 kg·m/s
Before calculating, explain the key idea from “Energy conservation” and which conditions must be checked.
The answer should show not only which rule is used for “Energy conservation”, but also why it is valid here.
Energy
Eight graded tasks from core fluency to exam-style application. Work independently before opening a hint or answer.
A 9 kg mass moves at 5 m/s. Find kinetic energy.
Ek=1/2 mv².
Ek=112.5 J.
A machine transfers 1000 J in 10 s. Find power.
P=E/t.
P=100 W.
Structure a solution for “Efficiency”: givens, SI units, law, substitution, and interpretation.
State the law before substituting numbers.
A full solution states symbols/units, selects a valid law for “Efficiency”, shows substitution and calculation, and interprets the result.
Identify three uncertainty sources in measuring “Work done” and improve each one.
Consider instrument resolution, reaction time, repeats, and controls.
A full response links each specific error source to a targeted improvement and identifies random or systematic impact.
Plan a suitable graph for “Energy resources” data and explain how to obtain a gradient or relationship.
Put the independent variable on x and dependent variable on y.
A full response labels axes/units, uses a suitable scale and best fit; gradient uses a large triangle and is interpreted with units.
Check whether a result for “Sankey diagrams introduction” is sensible using units, order of magnitude, and a limiting case.
A check should not merely repeat the same calculation.
A full check confirms dimensions/units, compares expected magnitude, and tests behaviour when one variable becomes very small or large.
Connect “Energy stores and pathways” to energy conservation or a force/field model and justify the choice.
Define the system and interactions.
A full response defines the system, describes transfer or interaction, applies the appropriate model, and states losses or limitations.
Write a multi-step exam response about “Energy conservation” with calculation and evaluation.
Separate givens, model, calculation, result, and evaluation.
A full response includes an appropriate diagram/model, laws, algebraic rearrangement, SI substitution, suitably precise result, and evaluation of assumptions.
Energy
Six distinct assignments from core fluency to challenge, each with an estimated time, hint, and answer guide.
Homework 1: A 5 kg mass moves at 6 m/s. Find kinetic energy.
Ek=1/2 mv².
Ek=90 J.
Homework 2: A machine transfers 2400 J in 15 s. Find power.
P=E/t.
P=160 W.
Homework 3: Structure a solution for “Efficiency”: givens, SI units, law, substitution, and interpretation.
State the law before substituting numbers.
A full solution states symbols/units, selects a valid law for “Efficiency”, shows substitution and calculation, and interprets the result.
Homework 4: Identify three uncertainty sources in measuring “Work done” and improve each one.
Consider instrument resolution, reaction time, repeats, and controls.
A full response links each specific error source to a targeted improvement and identifies random or systematic impact.
Homework 5: Plan a suitable graph for “Energy resources” data and explain how to obtain a gradient or relationship.
Put the independent variable on x and dependent variable on y.
A full response labels axes/units, uses a suitable scale and best fit; gradient uses a large triangle and is interpreted with units.
Homework 6: Check whether a result for “Sankey diagrams introduction” is sensible using units, order of magnitude, and a limiting case.
A check should not merely repeat the same calculation.
A full check confirms dimensions/units, compares expected magnitude, and tests behaviour when one variable becomes very small or large.
50 minutes / 40 marks
A timed, full-mark self-assessment with model-answer guidance.
Start the timer when ready, work without notes, show every step, and open model answers only after finishing.
1. A 3 kg mass moves at 6 m/s. Find kinetic energy.
2 marksEk=54 J.
2. A machine transfers 1800 J in 15 s. Find power.
3 marksP=120 W.
3. Structure a solution for “Efficiency”: givens, SI units, law, substitution, and interpretation.
3 marksA full solution states symbols/units, selects a valid law for “Efficiency”, shows substitution and calculation, and interprets the result.
4. Identify three uncertainty sources in measuring “Work done” and improve each one.
4 marksA full response links each specific error source to a targeted improvement and identifies random or systematic impact.
5. Plan a suitable graph for “Energy resources” data and explain how to obtain a gradient or relationship.
4 marksA full response labels axes/units, uses a suitable scale and best fit; gradient uses a large triangle and is interpreted with units.
6. Check whether a result for “Sankey diagrams introduction” is sensible using units, order of magnitude, and a limiting case.
4 marksA full check confirms dimensions/units, compares expected magnitude, and tests behaviour when one variable becomes very small or large.
7. Connect “Energy stores and pathways” to energy conservation or a force/field model and justify the choice.
5 marksA full response defines the system, describes transfer or interaction, applies the appropriate model, and states losses or limitations.
8. Write a multi-step exam response about “Energy conservation” with calculation and evaluation.
5 marksA full response includes an appropriate diagram/model, laws, algebraic rearrangement, SI substitution, suitably precise result, and evaluation of assumptions.
9. Compare two methods for investigating “Power” and select the more reliable using criteria.
5 marksThe choice must use at least three comparable criteria and acknowledge one trade-off or limitation.
10. Create an extension question about “Efficiency”, a prediction, and a data-collection plan.
5 marksA full response gives a testable question, justified prediction, independent-variable range, repeats, and an analysis method.
Unit
Curriculum reference sources. Always confirm the teaching sequence with the school and tutor.
Physics
Link each topic to equations, units, data handling, and required practical thinking.
The structure follows the official textbook layout and is used to organise study.
The areas that usually create mistakes or need extra revision.
Where to start: textbook, daily material, PDFs, videos, and worked examples.
Targeted practice before full tests so coverage is clear.
How to measure progress in this chapter and when it enters a cumulative mock.
What to do after finishing the chapter and how it connects to the next unit.
Note: for the official examinable syllabus of each school year, always confirm with the school, tutor, and current Ministry/IEP announcements.
