A 225Kg crate rests on a surface that is inclined above the horizontal at an angle of

Question:

A 225Kg crate rests on a surface that is inclined above the horizontal at an angle of 20.0o. A horizontal force (magnitude = 535N and parallel to the ground, not the incline) is required to start the crate moving down the incline. What is the coefficient of static friction between the crate and the incline?