Elastic collision:
- Momentum is conserved โ
- Kinetic energy is ALSO conserved โ
- Objects bounce apart
- Example: Newton's cradle (approximately), snooker balls
Inelastic collision:
- Momentum is conserved โ
- Kinetic energy is NOT conserved โ (some converted to heat/sound)
- Objects may stick together or deform
- Example: car crashes, catching a ball
๐ก Key point: Momentum is ALWAYS conserved in collisions (closed system). Kinetic energy is only conserved in perfectly elastic collisions (rare in real life).
This key facts covers Elastic vs Inelastic Collisions within Impulse & Collisions for GCSE Physics. Revise Impulse & Collisions in Forces for GCSE Physics with 13 exam-style questions and 10 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 6 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Impulse & Collisions
Which equation correctly defines impulse?
Explain how an airbag reduces the risk of injury to a driver in a collision.