1.27P Conservation of momentum
Conservation of momentum means total momentum before an event equals total momentum after it when no external force acts on the system.
- Syllabus
- 2024
- Objective
- 1.27
- Level
- —
Exam analysis
Chance of appearing23%of analysed past papers
Latest appearanceNovember 2024
Most common paperPaper2P
Typical marks1–4
Common command terms
- Calculate
- State
Scoring notes
- Common mistake
- Writing only that momentum is conserved without stating total momentum before equals total momentum after.
Recent exam appearances
November 2024Paper2P [null] · TZ06(b)(iii)[ 2 ]1.27P Conservation of momentum
November 2024Paper2P [null] · TZ06(a)[ 1 ]1.27P Conservation of momentum
May 2024Paper2PR [null] · TZ05(c)[ 4 ]1.27P Conservation of momentum
June 2022Paper2P [null] · TZ02(b)(ii)[ 3 ]1.27P Conservation of momentum
June 2022Paper2P [null] · TZ02(b)(i)[ 1 ]1.27P Conservation of momentum
Practice this objective
Coverage 2019–2024 · Updated 16 Jul 2026
1.27P Conservation of momentum
Use the conservation of momentum to calculate the mass, velocity or momentum of objects
Concept essentials
- Momentum conservation compares the total momentum of a system before and after an event.
- The principle applies only when external forces are absent or negligible.
- Momentum is directional, so signs or stated directions must be handled consistently.
- Explosions from rest produce equal and opposite total momenta after the event.
- Unknown velocities are found by combining conservation of momentum with p = mv.