1. The problem statement, all variables and given/known data Albert is pushing a 1.8 kg book against a vertical wall at an angle of 30.0 degrees. If the coefficient of static friction is 0.47 and kinetic friction is 0.35, how hard does Albert need to push the book to allow it to slide down the wall at a constant speed? 2. Relevant equations Fnet = ma uK = Fk/Fn (coefficient of kinetic friction) uK = Fs/Fn (coefficient of static friction) 3. The attempt at a solution If there was no angle involved, I know that I'd first calculate Fk (force of kinetic friction) as it is equal to Fg (force of gravity). Then using the formula for the coefficient of kinetic friction, I would rearrange to solve for Fn (normal force) since Fn = Fa (force applied) which would get me the answer. However, I have no idea how to factor in the angle given in this question to solve the problem since I have not done any forces questions involving angles. Thank you in advance!