What drawing stress is required to reduce a rod from 100 mm to 70 mm in a conical die with 30° included angle? Assume that tire friction coefficient is 0.05 and that the material is rigid-perfectly...

What drawing stress is required to reduce a rod from 100 mm to 70 mm in a conical die with 30° included angle? Assume that tire friction coefficient is 0.05 and that the material is rigid-perfectly plastic with a tensile yield stress of 160 MPa. What is the maximum reduction that can be achieved under these conditions?