$11\mathrm{.}1$ A $2-$in$.-$diameter AISI $1020$ steel rod is $10$ ft long. Under an

applied load, the rod elongates by $0\mathrm{.}48$ in$.$

$($a$)$ Compute the axial $($longitudinal$)$ strain in the bar.

$($b$)$ If the transverse deformation of the rod is $0\mathrm{.}0024$ in$.,$

compute Poisson's ratio for the material.