A crate of mass m is stationary on a ramp which is raised at an angle 0. a. Sketch a free body diagram of the crate at rest. b. What is the magnitude of the friction force? C. To move the block, the ramp is raised slowly. If the coefficient of static friction is , derive an expression for the angle at which the crate will begin to move. If the ramp is raised to an angle 02, above this critical angle, how long will it take the crate to slide through a distance s? The coefficient of dynamic friction is k. [0 = tan- - Ms,2s/g(sin 0 k cos 0)]