Design a screw jack for lifting a load of 50 kN through a height of 0.4 m. The screw is made of steel nd nut of bronze. Sketch the front sectional view. The following allowable stresses may be assumed : Compressive stress = 80 MPa ; Shear stress = 45 MPa For steel For bronze : Tensile stress = 40 MPa ; Bearing stress = 15 MPa Shear stress = 25 MPa. %3D The coefficient of friction between the steel and bronze pair is 0.12. The dimensions of the swivel base may be assumed proportionately. The screw should have square threads. Design the screw, nut and handle. The handle is made of steel having bending stress 150 MPa (allowable).