A stone is shot upwards with a speed of 20 m/s from a tower $200\;m$ high . The speed with which the stone strikes the ground is approximately .

Question

$\begin{array}{1 1} (a) \;60\;m/s \\ (b) \;65\;m/s\\ (c) \;70\;m/s\\ (d) \;75\;m/s\end{array} $