Make sure to run the command pip install fplot at the console panel to install this package. You would need to do this only once with your computer connected to a stable internet. After that you would need to use import folot as $fI$ in your code to access the $p$ lot function in this library.

Starting from rest, the velocity attained by a falling body of mass $m$ after $t$ seconds of flight is expressed by the following expression:

$v=\sqrt[\phantom{2}]{\frac{gm}{c_d}}tanh(\sqrt[\phantom{2}]{\frac{g{c}_d}{m}}t)$

where the acceleration due to gravity, $g=9\mathrm{.}81\frac{m}{s^2}$ and the drag coefficient $c_d=0\mathrm{.}25k\frac{g}{m}.$