# A large cargo ship and a small speedboat are both travelling at the same velocity across a harbour. Explain why the cargo ship is much harder to stop than the speedboat.

> Cambridge International IGCSE Physics (0625) — 1.6 Momentum · Explain · 4 marks

## Mark scheme (4 marks)

1. Momentum is the product of mass and velocity
2. The cargo ship has a much greater mass than the speedboat
3. Because velocity is the same, the cargo ship has much greater momentum than the speedboat
4. A greater force (or longer time) is needed to change (reduce to zero) the momentum of the cargo ship

## Key terms

- [velocity](https://www.gradenine.co.uk/glossary/velocity)

## Related

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-large-cargo-ship-and-a-901152a3) · Published by Druglandscape Ltd.