- #1

Zack K

- 166

- 6

## Homework Statement

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?

## Homework Equations

Eff=(Wout/Win) x100

W= Fxd

F=ma

## 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.