IB DP Physics (2025) A2.7 Momentum, Impulse & F = Δp/Δt

IB DP Physics lesson pack on momentum, impulse and F = Δp/Δt, Topic A.2 Forces and momentum, SL and HL, first assessment 2025: why a cushion saves an egg. Editable worksheet, 46-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

• Momentum p = mv as a vector, constant while no resultant external force acts.
• Newton’s second law as F = Δp/Δt, with F = ma its special case for constant mass.
• The resultant force as the gradient of a momentum-time graph.
• Impulse J = FΔt: the change in momentum, and the area under a force-time graph.
• The landing trap: a floor pushes with the average resultant force plus the weight.

IB skills (Tool 3: Mathematics, with Inquiry 2: Collecting and processing data):

• Multiply vectors by a scalar (taught).
• Interpret features of graphs: gradient, intercept and area under the graph (practised).
• Select and manipulate equations (practised).
• Linearize graphs, only where appropriate (practised).
• Draw lines of best fit (practised).
• Identify and justify the removal of outliers in data (practised).

What’s included:

• Student Worksheet - 17 pages
• Teacher Key - 29 pages
• Worked Solutions - 19 pages
• Assessment - 13 pages
• Lesson deck - 46 slides

Nine structured questions and four multiple-choice items: 73 marks across 34 parts, and eight figures, four with teacher-only answer layers stripped from the student copy rather than hidden. Five questions, thirty marks, are worked in the room and one multiple-choice item is the exit ticket; the rest go home, including a data question that straightens a curve, reads a change in momentum off the gradient and traces a non-zero intercept to a timing error.

It opens on an egg and a stone egg dropped side by side, and answers both questions once F = Δp/Δt is on the page. A Nature of Science note covers models and their limits. Free-body diagrams and F = ma are assumed rather than taught again, and collisions and explosions are not covered. 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:

• Upthrust, Viscous Drag and Terminal Velocity, the lesson before this one
• Newton’s Second Law: F = ma, the form this lesson generalises
• Resultant Force, Inertia and Newton’s First Law, where zero resultant force is taught
• The Units of a Quantity, base and derived units (free)

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