Ok, before i start i'd like to say i'm totally confussed about how to use use the friction formulas in my book...i say this because all my answers are wrong! Ok so what i need is help in the form of examples...and alot...cause my book doesn't offer anything. Anyhoo, heres's a problem i'm trying to solve: ( i rounded off the numbers for clarity) A block is at rest on an incline 30 degrees. weight 10kg Us .50 Uk .40 What is the frictional forces acting on the the 10kg mass. Answer in units of N Someone help clarify a plan of attack...in meantime im gonna try reading this chapter some more.