1. The problem statement, all variables and given/known data A wooden roof is sloped at a 44 deg angle. What is the minimum coefficent of static friction between the sole of a roofer's shoe and the roof if the roofer is not to slip? 2. Relevant equations coefficient of static friciton = friction force / Normal force 3. The attempt at a solution Well the mass isn't given so initially I thought it just wanted an equation. But after some workings here is what i got. coefficent of static friction = Fg sin44deg/ Fg cos44deg = 0.9657 I am not sure if this is the minimum or even the right answer. From my understanding, at the angle of inclination of 44deg an object which is on the incline at rest ...between the incline and the bottom of the object (in this case the roofers shoes) should have atleast a coeff of static friction of 0.9657 to stop from sliding. can someone elaborate to help me understand? For the same problem( with same weight) if the sole of the shoes were higher quality the coeff of static friction could be 0.98 right? One problem I have is, when I raised the angle to 50deg I get a value over 1 which is not right. I want to follow this up with the concept of kinetic friction. But I will when I solve the above problem. Thank you for taking the time to help me.