1. The problem statement, all variables and given/known data A book of mass M = .55 kg rests on a table where the coefficient of static friction us = .45. A force, F = 4 N acts on the book at an angle of 15 degrees above the surface of the table. What is the acceleration of the book if the coefficient of kinetic friction uk = .23? 2. Relevant equations ΣFx = ma ΣFy = ma Ff = Fn(uk) 3. The attempt at a solution I drew free body diagrams. ΣFx = Fx - Ff Fx - Ff = ma(x) Fx - Fn(uk) = ma(x) ΣFy = ma Fn - Fy - mg = ma(y) I'm not sure where to go from here. I know that I need to use Pythagoras theorem when I have the values of a(x) and a(y) but I don't know how to get that far. Please help, I've been working on this for 2+ hours.