A. As the lead design engineer for a lifting company, you are required to design a lead screw for an industrial application. It must have square threads with a pitch of 3mm and a mean diameter of 12mm. the coefficient of friction for the material is 0.2. Calculate the torque requirement of the driving motor when the load is 5 kN. B. The main agitator mechanism for an industrial dough mixer makes use of a screw jack used to raise and lower a load by applying an effort through a lever. The system has the following characteristics: Load to be raised 5000 N - Thread pitch 10 mm. Thread diameter 50 mm Coefficient of friction 0.15 Radius of lever 400 mm Calculate the efficiency to raise the load.