1. The problem statement, all variables and given/known data A 115 kg mail bag hangs by a vertical rope 3.8m long. A postal worker then displaces the bag to a position of 2.2m sideways from its original position, always keeping the rope taut. What horizontal force is necessary to hold the bag in the new position? 2. Relevant equations 3. The attempt at a solution Ok, so I set up the new position of the bag and used Pythagoreans theorem to find that the bag is now .7m higher than it was where it started. I called the original position my reference line so it has no potential energy there. At a height of .7 it has .7*9.8*120 In my book it says that F(in x direction) = -(change in potential)/(change in x) so I thought dividing this potential energy I found by the change in the x direction (2.2) would give me the Force in the horizontal?