6. If a member carries a tensile force P on its area of cross-section A, the normal stress introduced on an inclined plane making an angle ? with its transverse plane, is
8. A simply supported wooden beam 150 cm long and having a cross section 16 cm x 24 cm carries a concentrated load, at the centre. If the permissible stress ft = 75 kg/cm2 and fs = 10 kg/cm2 the safe load is