Question

find axial stress

Answer 1

when you calculate for dM
in 2nd step dM\[\int\limits_{0}^{b}x^2 \sigma d x \] i cant figure out how x^2 pops out
need help here ...

Answer 2

apart from previous one I have another conceptual doubt suppose this is a slender rod ,acted by tensile load P as previous and if I want to calculate axial stress at area b*b
then whats is area should be taken whether its 4b^2 or b^2 ? I mean whole or the concerned area.....