A block of mass m rests against a spring with a spring constant of k on a rough inclined plane which makes an angle of θ degrees with the horizontal. The block compresses the spring a distance d from its neutral position, and friction is preventing the block from moving up the ramp. Use Fsp as the spring force, Fs for the force of static friction, and Fk as the force of kinetic friction. Set your coordinates to have the x-axis along the surface of the plane, with up the plane as positive, and the y-axis normal to the plane, without as positive. Denoting the coefficient of static friction by us, Write an expression for the sum of the forces in the x-direction just before the block begins to slide up the inclined plane. Use defined quantities and g in your expression.
