Explicação:

x=8000m

t=3min e 20s=180+20=200s

v=?

v=x/t

v=8000/200

v=40m/s

[tex]\Large\displaystyle\text{$\begin{gathered}\boxed{\boxed{\sf V_m=\frac{\Delta S}{\Delta t} }}\\\begin{cases}\sf V_m=?\,m/s\\\sf\Delta S=8000\,m\\\sf\Delta t=3\,min\,e\,20\,s=200\,s\end{cases}\end{gathered}$}[/tex]

[tex]\Large\displaystyle\text{$\begin{gathered} \sf{ V_m=\frac{8000\,m}{200\,s}} \\ \therefore\underline{\boxed{\boxed{\sf{V_m=40\,m/s} }}} ~~(\checkmark)\end{gathered}$}[/tex]