England · Forces and motion · Unit FM-U4

Newton’s laws and stopping

A proposed unit with 3 lectures, independent practice and a unit assessment.

Unit scope

Filters show lectures with relevant core content. Mixed lectures retain clearly labelled Higher/separate extensions; those extensions are not required on other routes. Difficulty is a design rating, not a GCSE grade.

Lectures

FM-U4 · Newton’s laws and stopping

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FM-11 · FM-U4 · Planned

Newton’s first and third laws

  • ScopeShared + Higher vocabulary
  • Difficulty2 / 4 · proposed
  • Time25–30 min · estimated
  • StatusPlanned

Learning objectives

Apply first-law motion rules; identify third-law pairs acting on different objects; H: explain inertia.

8463 §§4.5.6.2.1,4.5.6.2.3 / 8464 §§6.5.4.2.1,6.5.4.2.3

DfE single-science pp.35–37 / Combined pp.30–32. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.6.

Needs firstFM-03,FM-07

Explanation

Newton’s first law concerns forces on one body and unchanged velocity when their resultant is zero. Third-law pairs act on different bodies, so they do not cancel each other in a free-body diagram for a single object.

Concepts, equations and units: Zero resultant → unchanged velocity; interaction forces equal/opposite on different bodies; N.

Prediction, demonstration and game exercise

Predict, observe, explain

Predict a low-friction cart continuing after a push; compare book–table interaction with forces on the book.

Planned learner game exercise

Sort force-pair cards and remove an erroneous arrow from a selected free-body diagram.

Independent practice

Explain three equilibrium/motion cases including a steady-moving cart.

Original practice example · Shared

A book rests on a table. Is the book’s weight and the table’s force on the book a third-law pair?

Show working and model answer

Working / reasoning

Both act on the book. The partner of table-on-book is book-on-table; the partner of Earth-on-book is book-on-Earth.

Answer

No. Each third-law pair acts on two different bodies.

Exit check and success criteria

Two accurate cases plus a third-law pair on distinct bodies; H vocabulary used meaningfully.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

A continuing force is required for steady velocity; weight and normal force on a book are a third-law pair.

Practical preparation

Optional cart and force-sensor demonstrations.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

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FM-12 · FM-U4 · Planned

Newton’s second law: acceleration investigation

  • ScopeShared + Higher extension
  • Difficulty3 / 4 · proposed
  • Time35–40 min · estimated
  • StatusPlanned

Learning objectives

Use F=ma; design force and mass comparisons; H: explain inertial mass as F/a.

8463 §§4.5.6.2.2 / 8464 §§6.5.4.2.2

DfE single-science pp.35–37 / Combined pp.30–32. Evidence checked 30 September–1 October 2026. Skills: WS2.1–2.7,3.5,3.7; MS3a–3c,4c.

Needs firstFM-09,FM-11

Explanation

Acceleration depends on the resultant force and the total accelerating mass. In a controlled test, vary only force or mass and track the full system. Friction and changing hanging mass can otherwise invalidate a claimed fixed-mass comparison.

Concepts, equations and units: F=ma; N, kg, m/s²; a∝F at fixed mass, a∝1/m at fixed F; inertial mass H.

Prediction, demonstration and game exercise

Predict, observe, explain

Show light gates/trolley/hanging-mass arrangement; include accelerating total mass and friction controls.

Planned learner game exercise

Plan two investigations varying resultant force or total mass; collect repeated accelerations.

Independent practice

Calculate three values, graph a–F and a–1/m, evaluate friction bias.

Original practice example · Shared

A 2 kg trolley system has resultant force 6 N. Find acceleration.

Show working and model answer

Working / reasoning

a = F/m = 6/2.

Answer

3 m/s².

Exit check and success criteria

Two calculations correct plus a controlled plan for both comparisons; H ratio explained.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Use driving force rather than resultant; changing hanging mass without tracking total mass is a fair fixed-mass test.

Practical preparation

RP-P7/RP-C19; AT1,2,3.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

FM-13 · FM-U4 · Planned

Reaction time and safe stopping

  • ScopeShared + Higher extension + Separate Physics stopping graphs
  • Difficulty3 / 4 · proposed
  • Time35–40 min · estimated
  • StatusPlanned

Learning objectives

Separate thinking/braking distance; explain road, tyres, brakes and human factors; H: estimate deceleration forces.

8463 §§4.5.6.3.1–4.5.6.3.4 / 8464 §§6.5.4.3.1–6.5.4.3.4

DfE single-science pp.35–37 / Combined pp.30–32. Evidence checked 30 September–1 October 2026. Skills: WS1.5,2.2,3.4,3.7; MS2b,2c,2f,2h,3c.

Needs firstFM-09,FM-12,EN-05

Explanation

Thinking distance is travel before braking starts; braking distance is travel while the brakes reduce kinetic energy. Human factors change reaction time; road and vehicle condition change braking. A fixed-braking-force model makes braking distance grow with speed squared.

Concepts, equations and units: Stopping distance=thinking+braking; thinking distance≈v t_reaction; typical reaction times 0.2–0.9 s; KE and work models; H force estimate.

Prediction, demonstration and game exercise

Predict, observe, explain

Compare identical speeds with different reaction times and surfaces; expose simulated human delay rather than measuring network lag.

Planned learner game exercise

Test a virtual road safety plan with distraction, tiredness, weather and tyre-condition cards; propose a ruler-drop method.

Independent practice

Summarise reaction-time repeats with mean/mode/median and histogram; plan representative participant sampling; calculate stopping distances. P: interpret speed–stopping-distance graphs for multiple vehicle types and estimate emergency-stop distances for a typical speed range. H: estimate forces.

Original practice example · Shared

At 15 m/s with reaction time 0.40 s and braking distance 18 m, find total stopping distance.

Show working and model answer

Working / reasoning

Thinking = vt = 15 × 0.40 = 6 m; stopping = 6 + 18.

Answer

24 m.

Exit check and success criteria

Two correct distances plus two causal factors and one data limitation; H estimate states assumptions.

During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.

Misconceptions, practical links and mastery

Check these misconceptions

Wet roads slow reactions; doubling speed only doubles braking distance under a fixed braking-force model.

Practical preparation

Optional teacher-supervised reaction-time study; not an RP.

Virtual preparation and revision only. Required hands-on activities and school records remain separate.

Proposed mastery

0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.

Full lecture page →

Area capstone

Sources and full programme

Sources checked 30 September–1 October 2026. Specifications govern content; textbooks supplement it. England has no single prescribed Physics course book. The full planning document includes sourced comparisons of Collins separate Physics and Trilogy books, Hodder/Hachette Physics and Oxford Physics listings, with access/approval limitations.

Download the complete Markdown programme and coverage matrix

A subsection map is proposed coverage. Clause-level educator review, item moderation, model validation and hands-on provision remain release gates. No all-board alignment or exam-board endorsement is claimed.