1. The problem statement, all variables and given/known data A ladder having uniform density, a length of 3.4 meters and a weight of 121 N rests against a frictionless vertical wall, making an angle of 75 degrees with the horizontal. The lower end rests on a flat surface, where the coefficient of static friction is Mu = 0.400. A painter having a mass of 80 kg attempts to climb the ladder. How far up the ladder will the painter be when the ladder begins to slip? 2. Relevant equations Torque equations and frictional force equations 3. The attempt at a solution So using the torque equations I got x = [Fwall * 3.4 * sin(75) - 121 * (3.4/2) * sin(165)] / (80 * 9.81 * sin(165) Where x is the distance from the pivot point and Fwall = Frictional force. But I think I'm having a problem finding the frictional force. I know Frictional force = Mu(N) , where N is the normal force of the ground. So to find N I use the formula 121 + 80(9.81) which equals 905.8 and gives a frictional force of .4(905.8) = 362.32. But when I plug it in I get x = 5.6 m, which is taller than the ladder and leads me to believe that is not the right way to calculate the frictional force. So is that the right way to calculate the frictional force, or is there another way? Help is much appreciated.