# A hot-air balloon rises vertically from rest. For the first part of its ascent it accelerates upwards, then it travels at a steady velocity, and finally it decelerates to rest at a higher altitude. Describe what a velocity-time graph of the entire journey would look like, and state what feature of the graph could be used to find the total distance travelled.

> Pearson Edexcel International GCSE Physics (4PH1) — 1.2 Movement and position · Describe · 4 marks

> A hot-air balloon rises vertically from rest, accelerates upwards, then travels at a steady velocity, and finally decelerates to rest at a higher altitude.

## Mark scheme (4 marks)

1. The graph starts at the origin (velocity = 0 at time = 0) and the line rises with a positive gradient during the acceleration phase.
2. The line becomes horizontal (constant/zero gradient) during the steady velocity phase.
3. The line then falls with a negative gradient back to zero velocity during the deceleration phase.
4. The total distance travelled is found from the area under the velocity-time graph.

## Key terms

- [velocity-time graph](https://www.gradenine.co.uk/glossary/velocity-time-graph)
- [steady velocity](https://www.gradenine.co.uk/glossary/steady-velocity)
- [distance](https://www.gradenine.co.uk/glossary/distance)

## Related

- [Revision notes for Pearson Edexcel International GCSE Physics (4PH1)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-hot-air-balloon-rises-vertically-from-a7ca29dc) · Published by Druglandscape Ltd.