if an engine must do 500 joules to pull a 10 kg load up to a height of 4 meters, what is the efficiency of the engines?
The useful work done (the potential energy increase) is M g H = 392 J
The efficiency is (Work out)/(Work in) = 392/500 = __ %
The efficiency is (Work out)/(Work in) = 392/500 = __ %