A retractable seating system is moved from its stored position into position for use. Its control unit stores one operating record for each stage of the deployment.
The table gives the records for one complete deployment.
| Stage | Duration in s | Electrical input power in kW | Unwanted energy dissipated in kJ |
|---|---|---|---|
| release catches | 5.0 | 0.20 | 0.40 |
| extend seating | 20 | 1.2 | 6.0 |
| lock catches | 5.0 | 0.20 | 0.40 |
Calculate the overall efficiency of the retractable seating system during this complete deployment.
128 exam-style questions on Edexcel GCSE Physics 8.3 Power and efficiency, covering 8.3.1 Power and 8.3.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.