(A) Derive Euler's crippling load for a long column with both ends pinned. (B) A bar of length 4 m when used as a simply supported beam and subjected to a uniformly distributed load (UDL) of 30 kN/m over the whole span, deflects 15 mm at the centre. Determine the crippling or buckling loads when it is used as a column with the following end conditions: (i) Both ends pinned (ii) One end fixed and other end free, and (iii) Both ends fixed.