An electric vertical takeoff and landing (eVTOL) search-and-rescue aircraft is powered by a high-capacity lithium-metal battery pack. A conventional search-and-rescue helicopter is powered by a kerosene turboshaft engine.
Table 1 compares the eVTOL aircraft and the conventional helicopter.
Table 1
| Power source | Maximum rate of climb in m/s\text{m/s}m/s | Mass of power system in kg\text{kg}kg | Maximum range in km\text{km}km | Maximum power output in kW\text{kW}kW |
|---|---|---|---|---|
| Lithium-metal battery | 12.5 | 960 | 240 | 480 |
| Kerosene turboshaft | 9.5 | 320 | 960 | 360 |
Give two advantages of the conventional helicopter compared with the eVTOL aircraft shown in Table 1.
The mass of the battery system in the eVTOL aircraft is 960 kg960 \text{ kg}960 kg. The total mass of the eVTOL aircraft is 3200 kg3200 \text{ kg}3200 kg.
Calculate the mass of the battery system as a percentage of the total mass of the eVTOL aircraft.
A high-power charging dock has a power output of 160 kW160 \text{ kW}160 kW (160 000 W160\,000 \text{ W}160000 W).
Write down the equation that links energy transferred, power, and time.
Calculate the time taken in seconds to transfer 1.152×108 J1.152 \times 10^8 \text{ J}1.152×108 J of energy to the eVTOL aircraft's battery system.