d
\(\begin{array}{l}
Given\,that\,F\left( t \right) = {F_0}{e^{ - bt}} \Rightarrow m\frac{{dv}}{{dt}} = {F_0}{e^{ - bt}}\\
\frac{{dv}}{{dt}} = \frac{{{F_0}}}{m}{e^{ - bt}} \Rightarrow \int\limits_0^v {dv} = \frac{{{F_0}}}{m}\int\limits_0^t {{e^{ - bt}}} dt\\
v = \frac{{{F_0}}}{m}\left[ {\frac{{{e^{ - bt}}}}{{ - b}}} \right]_0^t = \frac{{{F_0}}}{{mb}}\left[ { - \left( {{e^{ - bt}} - {e^{ - 0}}} \right)} \right]\\
\Rightarrow \,v\, = \frac{{{F_0}}}{{mb}}\left[ {1 - {e^{ - bt}}} \right]
\end{array}\)