Q$2$: $(10$ points$)$ A $100$ mm long rod has a diameter of $15$ mm $.$ If an axial tensile load of $10$ kN is

applied to it$,$ determine the change in the diameter. $E=70$GPa, Poisson's ratio $=0\mathrm{.}35$

Q$3$: $(10$ points$)$ The cotter is used to hold the two rods together. Determine the smallest thickness $t$

of the cotter and the smallest diameter $d$ of the rods. All parts are made of steel for which the failure

normal stress is $500$ MPa failure shear stress if $373$ MPa $.$ Use a factor of safety$=2\mathrm{.}5$ in tension and

factor of safety in shear $1\mathrm{.}75.$