A solid round bar 3 m long and 5 cm in diameter is used as a strut. Taking E = 2.0 × 10^{5} N/mm^{2}, find the crippling load (kN) when (i) both ends are hinged, (ii) one end is fixed and the other is free, (iii) both ends are fixed and (iv) one end is fixed and the other is hinged (use L_{e} = L/√2).