1. The problem statement, all variables and given/known data A window cleaner uses a ladder of length L and weighs 200N. He places it agaisnt a wall where, at the point of contact the coefficient of static friction, [tex]\mu[/tex], is 0.4. Upon the ground is 0.6. The window cleaner has a mass of 80kg and is 0.8 of the way up the ladder when it begins to slip. At what angle to the ground did he set the ladder up? 2. Relevant equations so i know this is a limiting friction question so i need to use F=[text]\mu[/tex]R and the forces should balance finding the normal using some trig i should get the angle. 3. The attempt at a solution ok so i know the cleaner is 0.8L up the ladder and the weight of the ladder should act downwards 0.5L of the way up, so i have two downward forces of weight in different places on the ladder. Im having trouble putting the free body diagram together. i have a normal force resulting from the contact of the cleaner, two frictional forces one on the wall and one on the ground, (do i need further normal contact forces on the ground and against the wall?). Im not not sure how many total forces i have in order to resolve. could someone please help with the method desperate.