An electric motor, used to lift a heavy load, has an input energy transfer of 240 000 J240\,000\text{ J}240000 J per minute.
The motor has an efficiency of 0.75.
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 transferCalculate the useful output energy transfer per minute.
4000 J4000\text{ J}4000 J
60 000 J60\,000\text{ J}60000 J
180 000 J180\,000\text{ J}180000 J
320 000 J320\,000\text{ J}320000 J