The efficiency of a maching is 80%.determine the workdone by a person using his machine to raise a load of 200kg through a vertical distance of 3.0m.take g(10m/s)show full working.

Answer 1

increase of potential energy = m g h = 200 * 10 * 3 = 6,000 Joules
6,000 /0.80 = 7500 Joules