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AS 9702 · 3.3 · Dynamics · Lesson bundle

Conservation of momentum, collisions and explosions

The principle that closes the dynamics topic, made lesson-ready: for a closed system the total momentum is unchanged, a consequence of Newton's third law. Plan, worksheet with answers, slides, and a Connect-Extend-Challenge activity, built around the sticking-trolleys model and the site simulation Conservation of Momentum, separating what is always conserved from what is not.

Syllabus
9702, 3.3
Level
AS
Duration
60 minutes
Activity
Connect-Extend-Challenge
Core visual
Sticking trolleys: momentum unchanged
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Every part, two ways

Each part of the bundle opens right here on the site, projectable in any browser, and downloads as an editable file, never a locked PDF. Adapt them to your set, your timing and your school's calendar.

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Lesson plan

The 60-minute plan, with the principle and its condition, the Newton's-third-law link, collisions and explosions, elastic versus inelastic, three worked examples, examiner traps and differentiation.

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Worksheet and answers

Original AS questions across recall, an inelastic collision, an explosion, an elastic-or-inelastic test and reasoning, with a full worked answer key.

Present on site · or PowerPoint .pptx

Slides

Your actual slides, presented right in the browser, with the live simulation linked beneath; the download is fully editable.

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21st century skills activity

A Connect-Extend-Challenge routine with a response sheet and teacher model responses, plus the PIES rationale and a facilitation guide, so it runs faithfully.

The matching topic page and simulation

Send learners to the lesson online

This bundle pairs with the student topic page Conservation of momentum, which carries the interactive explanation, and with the site simulation Conservation of Momentum, which lets learners set the masses and velocities and watch the total momentum stay the same through a collision.

Open the topic page   Open the simulation

How it is built

Always momentum; only sometimes energy

The hardest idea here is that momentum is always conserved while kinetic energy may not be. The lesson holds a sign convention through every collision and uses the sticking-trolleys model so the difference between an elastic and an inelastic collision is concrete, not just a rule.

The Connect-Extend-Challenge routine then consolidates the whole dynamics topic and surfaces the deep energy question for each learner to name. It ships with the response sheet and teacher model responses, so it can be run faithfully.

Original work by the TheLucidSTEM team. Questions are written in the style of the papers; no past paper question is reproduced. Supplied in editable formats so you can adapt them freely.
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