A C-clamp, sown in the figure works like the upside down power screw. At the position shown, the clap exerts a clamping force of 9 kN on an object. It has trapezoidal threads of 12 mm outside diameter and 2 mm pitch. The coefficient of friction for screw threads is 0.12. If the force exerted by the operator at the end of the handle is P = 40 N, find the length of handle.