Impulse and one-dimensional momentum

What this note covers

1. Momentum is a signed vector quantity
2. Impulse links force to momentum change
3. Apply conservation only when the system permits it
4. Use energy to classify a collision, not replace momentum
5. Recoil and propulsion use the same momentum balance
6. Make force and collision measurements interpretable
7. Photon momentum and solar-sail recoil
8. Worked force–time evidence: impulse is an area, not a peak

8 sections · 10 key terms & formulas · 6 common mistakes