if 1000mj is placed into a coal-burning power station and 300mj is produced as energy, however 9650mj was lost in the process along with another 70mj what is the effiency of the coal curning power station?
efficiency = Energy out/Energy in
efficiency = 300/1000 = 0.3 or 30%
However, your energies don't balance 300 + 9650 + 70 > 1000
