Collisions: impulse, momentum and kinetic energy
H2 Physics lessons on force–time impulse, one-dimensional momentum conservation, elastic interactions and kinetic-energy change.
Learning goals
- Use impulse and momentum conservation in one-dimensional elastic and inelastic collisions.
Before you begin
Work through the lessons in order. Each one explains the idea, models the reasoning and gives you a chance to practise before the topic check.
How the ideas connect
- Impulse and force–time area
- Momentum conservation and one-dimensional interactions
- Perfectly elastic collisions and kinetic-energy change
Learn in order
Lesson route
Lessons
- 01Impulse and force–time areaWhy does the area of a force–time graph measure a change in motion?
- 02Momentum conservation and one-dimensional interactionsWhen is total momentum conserved during an interaction?
- 03Perfectly elastic collisions and kinetic-energy changeWhat distinguishes a perfectly elastic collision from other collisions?
Further lessons
- 04Momentum & ImpulseDefine momentum and impulse, use force–time graphs, and apply conservation of momentum to solve 1D collision problems (A Level Physics).
- 05Elastic & Inelastic CollisionsUse momentum conservation and impulse to solve 1D collision problems, and distinguish elastic, inelastic, and completely inelastic collisions (A Level Physics).
Check your understanding
Practice and check
Key ideas and reference
Use this Collisions: impulse, momentum and kinetic energy overview to choose the lesson you need. Definitions, diagrams, worked examples and practice are inside each lesson.
- Impulse and force–time area
- Momentum conservation and one-dimensional interactions
- Perfectly elastic collisions and kinetic-energy change
Syllabus and review details
The coefficient of restitution is not required. Use momentum conservation, the perfectly elastic relative-speed condition and a direct comparison of total kinetic energy.
Use written calculations, explanations and diagrams as well as the short topic check. Exam questions often combine several of these skills.
Checked against the 2027 syllabus
Course and syllabus information
- Course
- GCE A-Level H2 Physics
- Edition
- GCE A-Level H2 Physics 2027