According to Hooke's law, within elastic limit for elastic material, material act as a spring, which reforms its shape after we deform it by some external force. Hence, a restoring force occurs
$\therefore F =- kx \quad k =$ spring constant
$\therefore F \propto x$
(Take, $g =9.8\,ms ^{-2}$ and $\left.\pi=\frac{22}{7}\right)$

