- #1

- 73

- 0

## Homework Statement

Two boxes each of mass 12kg are raised 1.8m to a shelf. The first one is lifted and the second is pushed up a smooth ramp. If the applied force on the second box is 48N, calculate the angle between the ramp and the ground.

## Homework Equations

W = Eg = mgh for first (lifted) box

Trig to calculate angle

## The Attempt at a Solution

I first calculated the gravitational energy on the first box that is lifted:

Eg = (12kg)(9.8m/s^2)(1.8m) = 211.7N

Then, knowing that, used trig to calculate the angle between ramp and ground:

Sin (theta) = opposite (211.7N)/hypoteneuse(48N)

and, naturally, this does not compute, so where did I go wrong?