England · Energy · Unit EN-U2

Measuring energy and power

A proposed unit with 4 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

EN-U2 · Measuring energy and power

Unit page →

EN-04 · EN-U2 · Planned

Gravitational potential energy

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

Learning objectives

Calculate changes in GPE; predict proportional effects of mass and vertical height.

8463 §§4.1.1.2 / 8464 §§6.1.1.2

DfE single-science pp.34–35 / Combined pp.29–30. Evidence checked 30 September–1 October 2026. Skills: WS4.3–4.6; MS1c,3b,3c,4c.

Needs firstEN-03; P0 mass/units

Explanation

GPE change depends on vertical height change and the local gravitational field. Two paths to the same height give the same gravitational energy change, although friction may require additional input work on the longer path.

Concepts, equations and units: ΔE_p = mgΔh; E in J, m in kg, g in N/kg, vertical h in m; g supplied.

Prediction, demonstration and game exercise

Predict, observe, explain

Lift equal and unequal masses on two routes ending at the same height; compare the energy changes.

Planned learner game exercise

Set load mass and lift height to deliver a target GPE gain; choose a reference level.

Independent practice

Solve three conversions/rearrangements; graph E_p against h at fixed m and g.

Original practice example · Shared

A 2 kg load rises 3 m. Use g = 10 N/kg. Find its GPE gain.

Show working and model answer

Working / reasoning

ΔE_p = mgΔh = 2 × 10 × 3.

Answer

60 J.

Exit check and success criteria

At least two of three calculations correct with units and use vertical height.

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

GPE belongs only to the object; ramp length replaces vertical height; g is mass.

Practical preparation

Optional ramp/lifting energy investigation, AT1.

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 →

EN-05 · EN-U2 · Planned

Kinetic energy

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

Learning objectives

Calculate KE and infer square-law speed effects; explain energy changes in acceleration and impact.

8463 §§4.1.1.2 / 8464 §§6.1.1.2

DfE single-science pp.34–35 / Combined pp.29–30. Evidence checked 30 September–1 October 2026. Skills: WS1.2,3.5; MS3b,3c,4a.

Needs firstEN-04; P0 squares

Explanation

Kinetic energy grows linearly with mass but with the square of speed. If speed doubles while mass stays fixed, KE becomes four times greater. In braking, this energy transfers into the internal energy of brakes and surroundings.

Concepts, equations and units: E_k = ½mv²; J, kg, m/s.

Prediction, demonstration and game exercise

Predict, observe, explain

Compare carts at v and 2v with equal mass; measure model speed and reveal energies.

Planned learner game exercise

Tune mass and speed to a target energy; stop the cart in an absorber and account for the transfer.

Independent practice

Three KE questions, one solving for speed; compare E_k–v and E_k–v² plots.

Original practice example · Shared

A 4 kg cart travels at 3 m/s. Find its KE, then its KE at 6 m/s.

Show working and model answer

Working / reasoning

½ × 4 × 3² = 18 J; ½ × 4 × 6² = 72 J.

Answer

18 J and 72 J; doubling speed gives fourfold KE.

Exit check and success criteria

Two numerical answers correct and doubling speed identified as fourfold KE.

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

Doubling speed doubles KE; an impact destroys energy.

Practical preparation

Optional cart/light-gate data, AT1,3.

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 →

EN-06 · EN-U2 · Planned

Elastic energy

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

Learning objectives

Calculate elastic energy within the proportional range; distinguish extension from total spring length.

8463 §§4.1.1.2,4.5.3 / 8464 §§6.1.1.2,6.5.3

DfE single-science pp.34–35 / Combined pp.29–30. Evidence checked 30 September–1 October 2026. Skills: WS1.2,4.5; MS3c.

Needs firstEN-05; P0 squares

Explanation

Extension is the change from the spring’s unloaded length. The elastic-energy equation used here assumes the proportional range, so a spring cannot be treated as an unlimited energy store obeying the same rule at every stretch.

Concepts, equations and units: E_e = ½ke²; J; k in N/m, e in m. Equation conditional on proportional behaviour.

Prediction, demonstration and game exercise

Predict, observe, explain

Stretch/compress springs with different stiffness; mark original length and linear limit.

Planned learner game exercise

Choose k and extension to store a safe target energy; reject model settings beyond the stated validity range.

Independent practice

Calculate three energies and predict the effect of doubling extension; connect to force data later in FM-05.

Original practice example · Shared

A spring has k = 200 N/m and extension 0.10 m within its proportional range. Find stored energy.

Show working and model answer

Working / reasoning

E_e = ½ke² = ½ × 200 × 0.10².

Answer

1.0 J.

Exit check and success criteria

Two calculations correct, extension measured correctly and validity condition stated.

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 total length; all springs obey the formula for every extension.

Practical preparation

Preparation bridge to RP-P6/RP-C18 in FM-05; not completion here.

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 →

EN-07 · EN-U2 · Planned

Work and power

  • ScopeShared
  • Difficulty2 / 4 · proposed
  • Time30–35 min · estimated
  • StatusPlanned

Learning objectives

Calculate mechanical work and power; compare machines doing equal work in different times.

8463 §§4.1.1.4,4.5.2 / 8464 §§6.1.1.4,6.5.2

DfE single-science pp.34–35 / Combined pp.29–30. Evidence checked 30 September–1 October 2026. Skills: WS4.2–4.6; MS3b,3c.

Needs firstEN-04–06

Explanation

Work is energy transferred when a force causes displacement along its line of action. Power compares the rate of transfer. Two motors can do equal work while having different powers if their operating times differ.

Concepts, equations and units: W_work = Fs along force direction; P=E/t=W_work/t; J, N, m, s, W; 1 W=1 J/s.

Prediction, demonstration and game exercise

Predict, observe, explain

Two machines lift the same load; predict which is more powerful before timing them.

Planned learner game exercise

Configure a lifting machine to meet energy and time targets; maintain a ledger including friction.

Independent practice

Three work/power questions, including a rearrangement; explain why holding a stationary load does no mechanical work on it.

Original practice example · Shared

A motor lifts against 50 N through 2 m in 4 s. Find work and useful power.

Show working and model answer

Working / reasoning

W_work = Fs = 50 × 2 = 100 J; P = W_work/t = 100/4.

Answer

100 J and 25 W.

Exit check and success criteria

Two calculations with units and a correct equal-work/different-time comparison.

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

Power means total energy; weight W and work W have the same meaning; effort without displacement is work on the load.

Practical preparation

Optional load-lifting measurements, AT1,2,5.

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.