N°1- The drive shaft of a ship transmits a power of 5.9 kw to the propeller at a speed of 150 rpm and is subjected to an axial thrust of 1230 kN deriving from the propulsive action of the propeller itself; the axial thrust is supported by a pin with multiple washers with independent rubrication.Determine the number (z) of the washers and their dimensions, considering a specific pressure of 5.9 N / mm ^ 2 to be admissible.