(Solved): Question 2(2.5+3.5=6 marks ) a) A circular cross-section steel bar of 1m length is subjected to a ...

Question $$2(2.5+3.5=6$$ marks $$)$$ a) A circular cross-section steel bar of $$1\mathrm{m}$$ length is subjected to an axial compression force of 10 kN. Assume: Young Modulus of steel is $$200\mathrm{GPa}$$ and Yield stress is $$350\mathrm{MPa}$$. The two ends of the bar are pin-pin supported. Calculated the minimum radius of this bar to be safe and avoid failing. (2.5 marks) b) A rectangular cross-section ( $$50\mathrm{mm}?100\mathrm{mm}$$ ) has a circular hole ( $$30\mathrm{mm}$$ diameter) as shown in Figure Q2b below. Calculate the position of the neutral axis $$(X?X)$$ measuring from the bottom of the section in $$\mathrm{mm}$$ and the second moment of area about $$(\mathrm{X}?\mathrm{X})$$ in $${\mathrm{mm}}^4$$. (3.5 marks)