A stone of mass 20 g is projected from a rubber catapult of length 0.1 m and area of cross section 10^-6 m^2 stretched by an amount 0.04 m. The…

A stone of mass $\displaystyle 20$ g is projected from a rubber catapult of length $\displaystyle 0.1$ m and area of cross section $\displaystyle 10^{-6} \mathrm{~m}^2$ stretched by an amount $\displaystyle 0.04$ m. The velocity of the projected stone is \_\_\_\_ m/s. (Young's modulus of rubber $\displaystyle =0.5 \times 10^9 \mathrm{~N} / \mathrm{m}^2$ )