1. The problem statement, all variables and given/known data A 7.0 kg box is pushed up the ramp (height is 6 m and hypo is 12 m) in 3.25 s. If it requires a force of 40 N to push at a constant velocity, what is the efficiency of the ramp? 2. Relevant equations Eff=(Wout/Win) x100 W= Fxd F=ma 3. The attempt at a solution The problem I have is that I don't know if 40.0 N is the force for Wout or Win. But I am guessing that it is Win since it's the minimum force need to push at a constant velocity. Then to get Wout you find the Normal force of the box which is 7 kg x 9.8= 68.6 N then you use W=68.6 x 12= 823 J. 480/823=58% efficient. But of course that's not right.