# A delivery driver pushes a heavy box along a warehouse floor at a constant speed. Explain why energy is dissipated during this process and describe the effect this has on the efficiency of the transfer.

> Edexcel GCSE Physics (1PH0) — 8.1 Energy — forces doing work · Explain · 4 marks

> A delivery driver applies a horizontal force to push a heavy box along a rough warehouse floor. The box moves at a constant speed across the floor.

## Mark scheme (4 marks)

1. Friction is a resistive force acting against the motion of the box
2. Work is done against the resistive force, causing energy to be transferred as heat to the surroundings
3. This transferred heat energy is dissipated — it is spread out into the surroundings and cannot be recovered as useful energy
4. Because some input energy is wasted as dissipated heat, the useful output energy is less than the total input energy, so efficiency is less than 1 (or 100%)

## Key terms

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

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-delivery-driver-pushes-a-heavy-a0706ee5) · Published by Druglandscape Ltd.