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.
Angle of ramp, θ=tan-1(2/12)
Minimum force required (without friction), F = 65(9.8)sin(θ).
Friction force, f= 50N
Efficiency = useful force / total force
= F/(F+f)