Specific energy is the quantity of energy stored per unit mass of a power source. An engineering team is evaluating two different propulsion systems for a deep-sea Autonomous Underwater Vehicle (AUV) designed for long-endurance ocean floor mapping.
The table below provides details on the two potential systems:
| Propulsion system | Specific energy (MJ kg−1\text{MJ kg}^{-1}MJ kg−1) | Mass of energy source (kg\text{kg}kg) | Overall system efficiency |
|---|---|---|---|
| Silver-zinc battery pack | 0.45 | 180 | 85% |
| Hydrogen fuel cell | 120.0 | 2.5 | 48% |
Determine which propulsion system will give the AUV the greater range for its mission. Support your answer with detailed calculations of the useful energy delivered by each system.
26 exam-style questions on AQA GCSE Physics 1.2 Conservation and dissipation of energy, covering 1.2.1 Energy transfers in a system and 1.2.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.