# A car is travelling along a straight, level road. The driver presses the accelerator pedal so that the driving force from the engine becomes greater than the total resistive forces acting on the car. Explain what happens to the motion of the car, and describe what must happen to the forces for the car to then travel at a new, higher constant speed.

> Eduqas GCSE Physics — 3.1 Forces and their interactions · Explain · 4 marks

## Mark scheme (4 marks)

1. When the driving force is greater than the resistive forces, there is a resultant force acting on the car
2. A resultant force causes the car to accelerate (speed up)
3. As speed increases, resistive forces (e.g. air resistance/friction) also increase
4. For constant speed, the driving force must equal the (increased) resistive forces so the resultant force is zero

## Key terms

- [driving force](https://www.gradenine.co.uk/glossary/driving-force)
- [resistive forces](https://www.gradenine.co.uk/glossary/resistive-forces)
- [constant speed](https://www.gradenine.co.uk/glossary/constant-speed)

## Related

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-car-is-travelling-along-a-17c70f40) · Published by Druglandscape Ltd.