1. The problem statement, all variables and given/known data A uniform ladder of mass 12kg is 4.6m long. If it is lifted from a horizontal to a vertical position, how much work is done. 2. Relevant equations 3. The attempt at a solution I'm just not sure how to approach this problem. I'm guessing that I start off using centre of mass of the ladder to determine that the radius of the movement is half the length of the ladder, so 2.3m. Since the ladder travels in an arch as it moves to it's resting position, would the distance value be c/4=∏r/2, so c/4=3.6m ? Force = 12kg x 9.81m/s2 = 117.3N W=117.3N x 3.6m = 420J How does this look?