3 A box weighing 130 N is on a rough plane inclined at \(12 ^ { \circ }\) to the horizontal.
The box is held at rest on the plane by the action of a force of magnitude 70 N acting up the plane in a direction parallel to a line of greatest slope of the plane.
The box is on the point of slipping up the plane.

1. Find the coefficient of friction between the box and the plane. The force of magnitude 70 N is removed.
2. Determine whether or not the box remains in equilibrium.