This topic summary covers Topic Summary: Momentum within Momentum for GCSE Physics. Revise Momentum in Forces for GCSE Physics with 13 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 12 of 12 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 12 of 12
Practice
13 questions
Recall
6 flashcards
Topic Summary: Momentum
Key Terms
- Momentum: p = mv, vector, kg m/s
- Conservation: Total momentum unchanged in closed system
- Elastic collision: KE conserved too
- Inelastic collision: KE not conserved (momentum is)
Key Facts
- Momentum is a vector — direction matters
- Momentum ALWAYS conserved in closed system
- KE only conserved in elastic collisions
- Explosion from rest → equal and opposite momenta
Key Equations
- p = mv
- Total p before = Total p after
- Units: kg m/s (not N)
- Higher: F = Δ(mv)/Δt
Exam Tips
- Assign positive/negative directions first
- Write "momentum before = momentum after"
- State conservation explicitly in all explanations
- Momentum ≠ force — different units and concepts