IB DP Physics (2025) A3.1 Conservation of Energy

IB DP Physics conservation of energy lesson pack, Topic A.3 Work, energy and power, SL and HL, first assessment 2025: where the idea of energy comes from. It takes one of the guide’s guiding questions for the topic, how energetics can solve problems in kinematics, and answers it with a derivation the class works out itself. Editable worksheet, 49-slide lesson deck, teacher key, worked solutions and a questions-only assessment, supplied as self-contained HTML plus colour and black-and-white PDF.

What students learn

• Newton’s second law and v² = u² + 2as, for a block pulled up a smooth slope, combine into one relation with no acceleration in it.
• Its two sides named as work and the change in kinetic energy, then used to find a speed without the acceleration.
• Work transfers energy: the rope’s work goes partly into the block’s motion and partly into its height, mgΔh.
• What energy is, and the principle of conservation of energy, with “used up” and “the ability to do work” retired.
• Why a pendulum released from rest cannot come back higher, and where its energy goes as the swing dies away.

IB skills (Tool 3: Mathematics):

• Derive relationships algebraically (practised).
• Resolve vectors (practised).
• Select and manipulate equations (practised).

What’s included:

• Student Worksheet - 15 pages
• Teacher Key - 24 pages
• Worked Solutions - 16 pages
• Assessment - 10 pages
• Lesson deck - 49 slides

Six structured questions and five multiple-choice items: 43 marks across 25 parts, and six figures, two with answer layers stripped from the student copy, not hidden. Four questions, 26 marks, are worked in the room, with a pendulum released from a student’s nose and a multiple-choice exit ticket. The rest go home, including two exam-style questions: a bucket hauled to a scaffold and a ski tow.

Work is named here, not taught: W = Fs cos θ and the sign of work are left to a later lesson, and mgΔh stays energy stored by height until one names it. A Nature of Science box sets out why conservation is a principle resting on evidence, not a proof, and the teacher notes cover the pendulum’s apparatus and safety. Worksheet and deck open in any modern browser with nothing to install, and the worksheet is fully editable. SI units, IB notation and IB command terms throughout. Suitable for grades 11-12 (ages 16-19) as a lesson, cover lesson, homework or revision.

Related resources:

• Newton’s Second Law: F = ma, where the derivation’s starting point is taught
• SUVAT Equations I: The Fundamentals, where v² = u² + 2as is taught
• Resolving Vectors, the skill pack behind the weight resolved on the slope

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