An industrial application needs to change a transmission steel shaft had incidentally broken under torsional loading. After discussion, the engineering office opted for a new shaft in composite material. The mass of the cylindrical shaft shouldn't exceed 15.7kg. 1. Using the required guide lines, calculate the material efficiency factors Pmin and Pmax for an allowable strength of 900MPa. 2. If the maximum allowable shaft length is Lmax=1m, calculate the lowest diameter dmin might be considered for assembling the shaft. 3. Which values the P-factors take in " m,S,N " SI unit