Q$4($a$)$ The equation for bending stress in a loaded curved beam of constant cross section is given by

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$\backslash$sigma$=\backslash$frac$\{$M y$\}\{$A e$($R$-$y$)\}$

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Draw a neat, labelled sketch indicating what each variable in the equation represents and define each variable.

$($b$)$ The steel rod shown in Figure $4$ has a circular cross section. It is subjected to a bending moment, $\backslash ($ M $\backslash ),$ of $1\mathrm{.}5$ Nm $.$ Determine the stresses acting at points $\backslash ($ A $\backslash )$ and $\backslash ($ B $\backslash )($as given by the equation in part $($a$)).$

$(14$ marks$)$

Figure $4$ Circular rod subject to bending moment