1. The problem statement, all variables and given/known data A engine used to raise a lift is 60% efficient, and the lift's mass is 2000kg. How much energy would be needed to raise it to 10m? 2. Relevant equations Efficiency = energy output/ energy input *100 3. The attempt at a solution EP=mgh = 2000*9.8*10= 196000 J. Therefore, eff. = energy output/energy input *100 = (0.6=EOUT/196000 EOUT= 0.6*196000=117600 J Am I on the right track?