a 65 kg bag is dragged along a 12m ramp in order to get from the ground to the floor of the loading dock 2m above the ground. determine the efficiency of of the ramp. The frictional force acting on the bag is 50N due to the ramp.
I don't understand how to the find the energy output and input.
work in = drag force * length of ramp
(in other words the work done by the person dragging)
gain in PE = m g h = 65 * 9.8 * 2
efficiency = 100(gain in PE/work in)