A gas-fired power station has an efficiency of 0.45.
What is the input energy needed to obtain a useful output energy of 900 MJ900\text{ MJ}900 MJ?
Use the equation:
efficiency=useful output energy transferinput energy transfer \text{efficiency} = \frac{\text{useful output energy transfer}}{\text{input energy transfer}} efficiency=input energy transferuseful output energy transfer405 MJ405\text{ MJ}405 MJ
900 MJ900\text{ MJ}900 MJ
1350 MJ1350\text{ MJ}1350 MJ
2000 MJ2000\text{ MJ}2000 MJ