IB DP Physics (2025) A3.2 Work Done & Kinetic Energy

IB DP Physics work done and kinetic energy lesson pack, Topic A.3 Work, energy and power, SL and HL, first assessment 2025: W = Fs cos θ, the sign of work, and net work as the change in kinetic energy. Editable worksheet, 60-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

• W = Fs cos θ, from the component of a force along the displacement.
• Positive, zero and negative work: why none is done on a held barbell, or on a body moving in a circle.
• Net work equals the change in kinetic energy, so a braking force takes away the same energy over the same distance, not the same speed.
• Ek = p²/2m, and why the lighter of two bodies pushed apart gets more of the kinetic energy.

IB skills (Tool 3: Mathematics, with Inquiry 3: Concluding and evaluating):

• Resolve vectors (practised).
• Calculate with exponents and trigonometric ratios (practised).
• Select and manipulate equations (practised).
• Derive relationships algebraically (practised).
• Interpret features of graphs (practised).
• Propagate uncertainties in processed data (practised).
• Draw and interpret uncertainty bars (practised).
• Draw curves of best fit (practised).
• Extrapolate graphs (practised).
• Identify and discuss random and systematic errors (practised).

What’s included:

• Student Worksheet - 20 pages
• Teacher Key - 31 pages
• Worked Solutions - 22 pages
• Assessment - 15 pages
• Lesson deck - 60 slides

Nine structured questions and five multiple-choice items: 57 marks across 32 parts, and fourteen figures, one with an answer layer stripped from the student copy, not hidden. Six questions, 30 marks, are worked in the room; the rest go home, including two exam-style questions and a twelve-mark data question in the Paper 1B pattern: a glider pulled at an angle, one point to add with its error bar, a curve to draw and extend, and a systematic error to explain.

Constant forces only: work done by a varying force, potential energy by name and the energy accounting for friction are left to later lessons. 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:

• Energy and Its Conservation, the lesson before this one
• Gravitational and Elastic Potential Energy, the lesson that comes next
• Resolving Vectors, the skill pack behind F cos θ
• Measuring the Acceleration of Free Fall, where error bars are taught (free)

Updated 1 Nov 2026: please reprint.
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