An electric cable system raises either of two flood-barrier gates at constant speed. The input power and efficiency of the cable system remain constant while each gate is raised.
The input power is 8.0 kW and the efficiency is 0.75.
| Gate | Mass in kg\mathrm{kg}kg | Vertical distance in m\mathrm{m}m |
|---|---|---|
| A | 2800 | 3.5 |
| B | 1900 | 5.0 |
The gravitational field strength is 10 N/kg.
Calculate how much longer it takes to raise one gate than the other.
State which gate takes longer.
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.