A timber block 250 mm square is supported on each side by a steel plate 250 mm wide and \( t \mathrm{~mm} \) thick. Detennine the thickness I so that the assembly will supporn an axial load of 1200 kN without exceeding a maximum timber stress of \( 8 \mathrm{MN} / \mathrm{m}^{2} \) or a maximum steel stress of \( 140 \mathrm{MN} / \mathrm{m}^{2} \). For timber, \( E=10 \times 10^{3} \mathrm{MN} / \mathrm{m}^{2} \), for steel, \( E=200 \times 10^{3} \mathrm{MN} / \mathrm{m}^{2} \)
